Merge pull request 'v0.27.0 (#44): LLM-placed named map point markers' (#45) from feat/44-llm-map-pointers into master

- shared: 8 MarkerTypes + MARKER_TYPE_INFO (label/color/glyph); MapMarker;
  GameState.markers (required, [] at init); TurnResult.markers {add,remove};
  MarkerSpec/MarkerInfo; FNV-1a 4-char markerId; MAX_MARKERS=400.
- data: new public/region-centroids.json (1,800 anchors = largest-part centroid
  + spread ~0.1x min-bbox) built by new idempotent scripts/build-region-centroids.mjs.
- server: regions.ts centroid loader (public/ then dist/); engine applyTurnResult
  marker ops (remove -> owner-recompute -> add, jitter, cap, never throws);
  prompt documents the contract; buildUserPrompt carries markers; stub marker-free.
- client: WorldMap symbol layer rendered as canvas per-type icons (glyph CDN dead);
  hover tooltip shows name; click focuses owning nation.
- tests: 168 -> 189 (centroids script, regions centroids, db legacy, engine markers).

AGENTS.md

@@ -28,12 +28,23 @@ renders territorial ownership; the whole thing persists to SQLite and streams ov
 - Backend: Node 22 + Express — one process serving the built client, `/api` (REST), and `/sse`
 - Persistence: `better-sqlite3` (one row per game, full `GameState` as JSON)
 - Map: MapLibre GL (`maplibre-gl`) — remote OpenFreeMap `dark` basemap + a **sub-national**
-  choropleth from `public/regions.geo.json` (2,597 sub-regions; feature `id` = `<ISO_A3>-<nn>`,
-  `properties.parent` = the country's ISO_A3). Ownership and the LLM stay at **country**
-  granularity, so a sub-region inherits its parent country's owner color (see #16).
+  choropleth from `public/regions.geo.json` (1,800 sub-regions; feature `id` = `<ISO_A3>-<nn>`,
+  `properties.parent` = the country's ISO_A3). Ownership is at **region-key** granularity
+  (v0.19, #16 P1): every sub-region is addressed by a stable key from
+  `public/region-keys.json`, `Nation.territory` holds those keys, and each sub-region is
+  colored by its own owner. Since v0.21 (#16 P2) the LLM moves *individual* sub-regions
+  across shared land borders (frontier-biased transfers, verified with the `getNeighbours`
+  function-calling tool) instead of whole countries. Since v0.25 (#31) the old RU-ARK
+  mega-region is split into the mainland (`RU-ARK`, key unchanged) plus the New Earth
+  (`RU-ARK-NE`) and Severnaya Zemlya (`RU-ARK-SZ`) island groups; since v0.26 (#41) the
+  mainland's 28-part Arctic-coast band is further re-partitioned into Pechora (`RU-PEO`)
+  and Yamal (`RU-YAM`) (the 5-part lat < 68 core stays `RU-ARK`/`arkhangel-sk-lhbk`).
 - The LLM client is a thin OpenAI chat-completions wrapper over native `fetch` with an
-  **injectable transport** (mirrors `mesh-bot/src/llm`). A deterministic **stub** transport
-  (`LLM_STUB=1`) is used by all tests/e2e.
+  **injectable transport** (mirrors `mesh-bot/src/llm`), with two entry points: plain
+  `chat()` and `chatWithTools()` — a bounded OpenAI function-calling loop (max 6 tool
+  rounds, then one forced no-tools request) sharing the same retry/backoff/
+  `reasoning_effort` machinery (see the LLM config note below). A deterministic **stub**
+  transport (`LLM_STUB=1`) is used by all tests/e2e.
 
 ## Layout
 
@@ -45,22 +56,35 @@ history/
 ├── eslint.config.js        # flat config (ESLint 9)
 ├── tsconfig.json           # strict; aliases @/ → src/, @shared/ → shared/
 ├── vite.config.ts          # dev server + proxy /api,/sse → :4321; @ / @shared aliases
-├── vitest.config.ts        # unit tests (server/**/*.test.ts)
+├── vitest.config.ts        # unit tests (server/**/*.test.ts + scripts/**/*.test.ts; 189 tests)
 ├── playwright.config.ts    # deterministic e2e (webServer runs npm run dev, LLM_STUB=1)
 ├── index.html
 ├── presets/                # 5 scenario JSON files + index.json (manifest)
 ├── public/
 │   ├── countries.geo.json  # 177 countries, id=ISO_A3 (input to the region generator)
-│   └── regions.geo.json    # 2,597 sub-regions, id=<ISO_A3>-<nn>, parent=ISO_A3 (the choropleth)
+│   ├── regions.geo.json    # 1,800 sub-regions, id=<ISO_A3>-<nn>, parent=ISO_A3 (the choropleth)
+│   ├── region-keys.json    # feature id -> region key, 1,800 entries (the ownership/LLM address space, #16 P1)
+│   ├── region-adjacency.json # region key -> bordering region keys, 1,800 entries (the getNeighbours data, #16 P2)
+│   └── region-centroids.json # region key -> {lat,lon,spread} anchor for map markers, 1,800 entries (#44)
+├── scripts/                # the geo/manifest data pipeline — .mjs (turf allowed HERE only;
+│   │                       #   never imported by .ts): generate → coarsen → cleanup → smooth →
+│   │                       #   fill-gaps → split-arkhangel → split-arkhangel-band → build-region-keys
+│   │                       #   → build-region-adjacency → build-region-centroids
+│   └── *.test.ts           # turf-free vitest tests pinning the dataset + the manifests
 ├── shared/                 # NO runtime deps — the single source of truth
 │   ├── types.ts            #   domain types (Nation, GameState, RoundItem, Preset, …)
-│   └── protocol.ts         #   LLM TurnResult schema + AddAction/AddDiplomacy/RemoveQueueItem/Jump request types + pure helpers
+│   └── protocol.ts         #   LLM TurnResult schema (incl. `unowned`, v0.22 #16 P3, and
+│                           #     `nationOps`, v0.23 #16 P4a; v0.24 #16 P4b) + AddAction/AddDiplomacy/RemoveQueueItem/
+│                           #     Jump + NationOp confirm/reject request types + pure helpers
 ├── server/
-│   ├── index.ts            # Express: /api/* (action|diplomacy|queue/remove|jump|advisor|games|presets), /sse/:id; reads PORT/LLM_*/DATA_DIR
-│   ├── engine.ts           # pure: buildPrompt / parse+validate / applyTurnResult / runTurn / queueRoundItem / removeRoundItem / advisor
-│   ├── llm.ts              # LlmClient (injectable transport, retry+backoff, logging) + env config
-│   ├── stub.ts             # deterministic LLM transport (tests/e2e) + ADVISOR_MARKER
-│   ├── map.ts              # GameState → RegionMap (ISO_A3 → owner + stable color)
+│   ├── index.ts            # Express: /api/* (health|action|diplomacy|queue/remove|jump|advisor|
+│   │                       #   nation-op/confirm|nation-op/reject|games|map|presets), /sse/:id; reads
+│   │                       #   PORT/LLM_*/DATA_DIR
+│   ├── engine.ts           # pure: prompts / parse+validate / applyTurnResult (sole-ownership + no-man's-land releases, v0.22 #16 P3) / runTurn (tool path + plain fallback) / getNeighbours tool + executor / playerFrontier / queue ops / advisor / nation-op ops (resolveNationRef / freshNationId / NEW_NATION_STATS / applyNationOp rename+split+merge / confirmNationOp / rejectNationOp, v0.23 #16 P4a; v0.24 #16 P4b)
+│   ├── llm.ts              # LlmClient: chat() + chatWithTools() (bounded function-calling loop), injectable transport, retry+backoff, logging + env config
+│   ├── regions.ts          # turf-free region-key data access: load manifest/geo/adjacency (public/ then dist/), country→keys expansion, reference table, neighboursOf/hasAdjacency
+│   ├── stub.ts             # deterministic LLM transport (tests/e2e): one frontier conquest per turn + ADVISOR_MARKER
+│   ├── map.ts              # GameState → RegionMap (region key → owner + stable color)
 │   ├── presets.ts          # load preset JSON files from disk
 │   ├── db.ts               # SQLite open/save/load
 │   └── *.test.ts           # unit tests (vitest)
@@ -77,7 +101,8 @@ history/
         ├── PresetPicker.tsx / NationSelect.tsx   # home + nation pick screens
         ├── WorldMap.tsx     # MapLibre basemap + choropleth + click→dossier + hover tooltip + player highlight
         ├── NationPanel.tsx  # a nation's stats/territory/diplomacy dossier
-        ├── ActionPanel.tsx  # tabs: Action / Diplomacy / Advisor + pending-queue list (per-item trash button + confirm dialog) + "Jump forward"
+        ├── ActionPanel.tsx  # tabs: Action / Diplomacy / Advisor + pending-queue list (per-item trash button + confirm dialog) + "Jump forward" + "Nation proposals" trigger (v0.23 #16 P4a)
+        ├── NationOpDialog.tsx # review LLM-proposed nation ops (rename/split/merge) — confirm (editable rename/merge name, split successor radio) or reject (v0.24 #16 P4b)
         ├── EventFeed.tsx    # scrolling event log (newest first)
         ├── FloatingWindow.tsx # the HUD window primitive — free-floating (draggable, position persisted), or `pinned` (fixed top-center bar), or `dock`ed (full-height left/right column); renders dock controls when `onDockChange` is set
         ├── StatBar.tsx
@@ -91,10 +116,13 @@ history/
 | `npm run dev` | Express on :4321 (tsx watch) + Vite on :5173 (proxies `/api`,`/sse`) concurrently |
 | `npm run build` | `vite build` (client → `dist/`) then `tsup server/index.ts` → `server/dist/index.js` |
 | `npm start` | run the compiled server (`node server/dist/index.js`) on :4321 |
-| `npm test` | vitest unit tests in `server/` (39 tests) |
+| `npm test` | vitest unit tests (`server/` + `scripts/`; 189 tests) |
 | `npm run typecheck` | `tsc --noEmit` (strict) across src/server/shared/e2e/configs |
 | `npm run lint` | ESLint flat config |
 | `npm run e2e` | Playwright, fully deterministic (`LLM_STUB=1`); **runs in CI on every PR** (see below) |
+| `npm run split:regions` | (re)apply the #31 Arkhangel'sk split (`RU-ARK` → mainland + `RU-ARK-NE` + `RU-ARK-SZ`) — idempotent no-op once applied |
+| `npm run split:regions:band` | (re)apply the #41 Arctic-coast-band split (`RU-ARK` mainland's 28-part lat ≥ 68 band → `RU-PEO` + `RU-YAM`) — idempotent no-op once applied |
+| `npm run build:region-keys` / `build:region-adjacency` / `build:region-centroids` | (re)generate the `public/region-keys.json` / `region-adjacency.json` / `region-centroids.json` manifests — deterministic + idempotent (byte-identical re-run) |
 | `docker compose up -d --build` | prod image on :4321, routed via Traefik at `history.dev.kkhost.pl` |
 
 **Local verification (before every PR):** `npm run typecheck` + `npm run lint` + `npm test` (unit) + `npm run build`. The full **e2e** suite (`npm run e2e`) is verified by **CI on every PR** (the Playwright config boots its own dev webServer with `LLM_STUB=1`) — locally you only need the four checks above; e2e is the CI source of truth.
@@ -143,29 +171,152 @@ history/
   (model down) surfaces as an HTTP 502 to the client (shown as a toast).
 - **Stable per-nation colors.** `shared.nationColor(id)` hashes a nation id → hue, shared by the
   server's `RegionMap` and any client coloring so the choropleth always agrees.
-- **Map click → dossier target (owner resolved from the RegionMap, via the parent country).**
+- **Region-level territory (v0.19/v0.21, #16 P1+P2).** Since v0.19 ownership lives at sub-region
+  granularity: `Nation.territory` holds **region keys** (`<name-slug>-<4char>`, e.g. `moselle-rygy`;
+  the manifest is `public/region-keys.json`), `server/regions.ts` expands each preset's country list
+  to all its sub-regions' keys at game creation, and `buildRegionMap` keys the choropleth `RegionMap`
+  by region key. Since v0.21 transfers are **frontier-biased**: `applyTurnResult` is snapshot-first
+  and enforces **sole ownership** (a key transfers only when exactly one nation claims it to gain,
+  it has exactly one current owner, and the owner is not the gainer — a double claim is rejected and
+  a lone `lose` is a no-op, so a key can never be orphaned or duplicated), and the LLM can call the
+  `getNeighbours` tool (`GET_NEIGHBOURS_TOOL` + `makeNeighboursExecutor` in `engine.ts`, data from
+  `public/region-adjacency.json` via `neighboursOf`) to verify land borders before proposing a
+  transfer; the user payload carries the player's `frontier` (the sorted other-nation keys bordering
+  the player's territory, via `playerFrontier`). The tool path degrades gracefully: without the
+  adjacency manifest (or with a client lacking `chatWithTools`), a turn runs the legacy plain
+  `chat()` path and the tool/frontier simply switch off. Since v0.22 (#16 P3) a key may also end
+  a turn **unowned** — "no man's land": `TurnResult.unowned` lists keys released this turn;
+  `applyTurnResult` applies releases FIRST (a key leaves its sole owner — only a key with exactly
+  one current owner can be released; a never-assigned or corrupt key is a no-op), then claims
+  against the post-release snapshot, so a `gain` on an ownerless key is a **re-claim** (granted to
+  the sole gainer and removed from the cumulative `GameState.unowned` list). The user payload
+  carries the current `GameState.unowned` as `unowned`, and the jump route's `regions` reference
+  table includes those keys so the model can name them when re-claiming. The map renders a
+  released key in the distinct visible grey (`NO_MANS_LAND_FILL` in `shared/protocol.ts`, with a
+  "No man's land" tooltip sub-line) while a preset-unassigned key keeps the faint look ("No owner")
+  — the distinction is decided by the client from `GameState.unowned` (via `regionFillStyle` /
+  `unownedTooltipLabel`), never by the `RegionMap`, which only knows "owned" vs "absent". A fresh
+  game always starts with `unowned: []` (legacy SQLite rows load with it defaulted). Since v0.25
+  (#31) the 78-part RU-ARK mega-region is split into three features — mainland `RU-ARK` (its key
+  `arkhangel-sk-lhbk` is **unchanged**, so existing ownership is safe), `RU-ARK-NE` (New Earth /
+  Franz Josef Land, `new-earth-eikt`) and `RU-ARK-SZ` (Severnaya Zemlya,
+  `severnaya-zemlya-awqp`) — by the idempotent `scripts/split-arkhangel.mjs` stage (run between
+  `fill:regions` and `build:region-keys`, no-op once applied); the two island groups get their own
+  region keys and adjacency entries (New Earth is genuinely isolated → empty adjacency; Severnaya
+  Zemlya's islet rings touch the coarsened mainland ring, so it records one SZ↔mainland pair).
+  Since v0.26 (#41) the mainland's 28-part Arctic-coast band (centroid lat ≥ 68) is further
+  re-partitioned by the idempotent `scripts/split-arkhangel-band.mjs` stage (run between
+  `split:regions` and `build:region-keys`, no-op once applied) into Pechora (`RU-PEO`,
+  `pechora-qwhs`, 13 parts) and Yamal (`RU-YAM`, `yamal-gosw`, 15 parts) — a pure re-partition
+  (no geometry moved → the union is byte-identical) that keeps `RU-ARK`'s id/name/key
+  `arkhangel-sk-lhbk` stable and inserts the two new features immediately after `RU-ARK-SZ`; the
+  5-part lat < 68 core stays `RU-ARK` (a single ~305k km² polygon — splitting it needs turf
+  clipping, not a pure re-partition).
+- **Nation ops — “LLM proposes, player confirms” (v0.23, #16 P4a; v0.24, #16 P4b).**
+  `TurnResult.nationOps` (required in the schema) carries the LLM’s proposed **`NationOp`s** — a
+  discriminated union of `rename` / `split` / `merge`, all three of which are now applied on confirm
+  (P4b implemented split/merge). Each op names its target via `nationRef` — the LLM may use a
+  nation’s **id or name**; `resolveNationRef` resolves id-first, then a case-insensitive
+  unique-name match, and returns `null` for an unknown or ambiguous ref (such ops are dropped
+  defensively in `validateNationOps`, never thrown). A turn’s ops are appended to
+  `GameState.pendingNationOps`, which is **never cleared on a turn commit** — pending proposals
+  persist across turns until resolved (like the action queue). The player then decides per op via
+  `POST /api/games/:id/nation-op/confirm` (`{index, edits?{name?, playerPart?}}`) or
+  `.../nation-op/reject` (`{index}`): `confirmNationOp` applies the op to a clone — **rename** sets
+  `Nation.name` to the edited value or, failing that, the proposed `to` (id / territory / relations /
+  `playerNationId` stay valid, so a renamed player is re-named in place); **split** (the parent
+  must resolve and have ≥2 named parts, else a no-op) partitions the parent’s region-key territory
+  into new nations in parts order — each new nation gets a fresh id (`freshNationId`: first free of
+  `n1`, `n2`, …) and the baseline `NEW_NATION_STATS` (not a copy of the parent’s), plus a copy of
+  the parent’s relations; a key named by several parts goes to the first, and the parent’s
+  unclaimed keys go to part 0 (in territory order), so sole ownership holds and nothing is
+  orphaned; if the parent was the player’s nation, `playerNationId` moves to the part chosen by
+  `edits.playerPart` (clamped into range, default 0), which also receives `edits.name`; **merge**
+  (every ref must resolve, ≥2 DISTINCT inputs, and the survivor must be one of them, else a
+  no-op) folds the inputs into the survivor, which keeps its id and its own stats, gains the
+  union of the inputs’ territories (the survivor’s keys first) and a union of their relations
+  (the survivor’s own view of a third party wins, else the first input’s), is renamed
+  `edits.name` → `into` → its own name, while the other inputs are removed and their ids dropped
+  from every remaining nation’s relations maps; if the player led a removed input,
+  `playerNationId` moves to the survivor. An op that is invalid at confirm time (an ambiguous ref,
+  …) is a no-op on the world but is still removed — and `rejectNationOp` just drops it; both
+  splice by index and bump `version` once (an invalid index → `null` → HTTP 400). The response is
+  `{ game }` and the server broadcasts a version-bumped SSE `state`, so every tab’s
+  version-guarded `applyState` stays in sync. The client lists the pending ops in a “Nation
+  proposals” dialog (in the “Your move” panel): a rename and a merge show an editable name field
+  (the merge also highlights the survivor among the input chips); a split lists each part (name +
+  proposed region count) with a successor radio that appears only when the parent is the player’s
+  own nation (preselected part 0 — the choice is always valid). The system prompt documents all
+  three op shapes as a proposal queue (at most 1–2 per turn, each narrated in events). The stub
+  never proposes a nation op (`nationOps: []`), so this path is covered by unit tests only
+  (`server/engine.test.ts`).
+- **Map markers (v0.27, #44) — LLM-placed named points, region-anchored, canvas-icon rendered.**
+  The LLM can place named **point markers** on the map each turn: eight `MarkerType`s
+  (`city, factory, army, port, capital, fleet, rocket, gathering`; a **capital** is at most one
+  per nation, a **gathering** a political/social mass event that can enable a non-military
+  takeover). `TurnResult.markers = { add: MarkerSpec[]; remove: string[] }` (both required,
+  default `[]`; `MarkerSpec = { type, name, regionKey }`). A marker's stable `id` is the FNV-1a
+  32-bit hash of `` `${type}\u0000${name}\u0000${regionKey}` `` rendered as four lowercase
+  base-26 characters (mirroring the region-key scheme) — so a **re-add is idempotent** and a
+  **remove is unambiguous** (by id). `GameState.markers: MapMarker[]` is required (`[]` at game
+  creation; a legacy SQLite row without the field loads as `[]` — additive, never wipes).
+  `applyTurnResult` handles markers **after** territory claims: (1) remove by id (absent id →
+  no-op); (2) **recompute every surviving marker's `ownerNationId` from the final post-claim
+  ownership** — a marker always follows its region (a captured region follows its new owner; a
+  region released to no man's land, or a key with 0 or 2+ owners, becomes `null`); (3) add — each
+  new spec is placed at its region's centroid (from `public/region-centroids.json`, injected via
+  the optional `centroidOf` param on `applyTurnResult`) plus a deterministic per-axis jitter
+  (`spread ≈ 0.1 × the largest part's smallest bbox dimension`, so multiple markers of one region
+  scatter instead of stacking), owned by the region's post-turn owner, stamped with the acting
+  turn. Adds are **dropped, never thrown**, when the region key is unknown or has no centroid,
+  when the id already exists, or beyond the hard cap `MAX_MARKERS = 400`. The system prompt
+  documents the field + types + placement rules; `buildUserPrompt` carries the current markers
+  (as `MarkerInfo[]`) so the model can reference their ids in `remove`; a marker add/remove makes
+  a turn "meaningful". **Rendering is canvas-generated per-type ICON images, NOT text labels**
+  (`src/components/WorldMap.tsx`): every external glyph/font endpoint is a dead 404 (OpenFreeMap's
+  `fonts/{stack}/{range}.pbf` and `demotiles.maplibre.org/font/…`) and the OFM dark basemap only
+  renders because it is **raster** (labels baked into the tiles) — there is no working vector
+  font, so markers are drawn as self-contained, offline, deterministic per-type icons
+  (`drawMarkerIcon`: distinct shape per type, filled with the type color, outlined for legibility),
+  registered as named `ImageData` images that survive `styledata`. The marker **name shows in the
+  hover tooltip** (not a persistent on-map label), and **clicking a marker focuses its owning
+  nation's dossier**. There are **no separate marker event handlers** — MapLibre's per-layer event
+  delegates fire independently (no `stopPropagation`), so the region hover/click handlers instead
+  `queryRenderedFeatures` the marker layer under the cursor and act on the marker when present.
+  The **stub is marker-free** (`markers: { add: [], remove: [] }`) — e2e (CI, `LLM_STUB=1`) is
+  unaffected and the marker path is unit-tested only (`server/engine.test.ts`,
+  `scripts/region-centroids.test.ts`, `server/regions.test.ts`, `server/db.test.ts`).
+- **Map click → dossier target (owner resolved from the RegionMap, by region key).**
   Clicking a sub-region does NOT open a popup — it switches the dossier to that sub-region's
-  **parent country's** owning nation (`focusNation(ownerId)` in `GameScreen`, which also records
-  which region was clicked for a small dossier label); the manual "Inspect" selector and a map click
-  both set the same target and stay in sync (a manual pick clears the label). Ownership is resolved
-  from the authoritative `RegionMap` (keyed by the **parent country's** ISO_A3) via the feature's
-  `properties.parent`, using the shared `mapFeatureOwner()` helper (`regionId` still holds the
-  sub-region's own id, e.g. `FRA-03`). It must **never** be resolved from the feature's top-level
-  `id` (MapLibre repacks it into a numeric index — the "no owner" bug, #6) nor from the sub-region
-  `id` (not a `RegionMap` key). Sub-regions of a country with no `RegionMap` entry (unowned) leave
-  the current dossier target unchanged — never a broken dossier. The hover path (a non-closeable
-  tooltip showing the sub-region name + parent country + owner + key stats) uses the same resolution.
-  **PR 2 of #16:** the map renders `regions.geo.json` (sub-national) but ownership/territory and the
-  LLM stay at country level — a nation owns whole countries, so all its sub-regions share the country's
-  color, and a whole-country transfer flips all its sub-regions at once (PR 3 will make sub-regions
-  individually ownable).
+  owning nation (`focusNation(ownerId, {name})` in `App.tsx`, which also records which region was
+  clicked for a small dossier label); the manual "Inspect" selector and a map click both set the
+  same target and stay in sync (a manual pick clears the label). Ownership is resolved from the
+  authoritative `RegionMap` (keyed by **region key**) via the feature's stamped
+  `properties.regionKey`, using the shared `mapFeatureOwner()` helper (`shared/protocol.ts`) —
+  `WorldMap` stamps each rendered feature with its key from `region-keys.json` when it builds the
+  choropleth source. It must **never** be resolved from the feature's top-level `id` (MapLibre
+  repacks it into a numeric index — the "no owner" bug, #6) nor from the raw sub-region `id` (not a
+  `RegionMap` key). A sub-region whose key has no owner leaves the current dossier target
+  unchanged — never a broken dossier. The hover path (a non-closeable tooltip showing the region
+  name + owner chip + key stats) uses the same resolution. `properties.parent` is static
+  geographic-origin data — never use it for ownership or display.
 - **Deterministic stub.** `server/stub.ts` answers the model contract deterministically per
   queued round item: each `action` item → one military/success event, each `diplomacy` item → one
   diplomatic/partial event, an empty round → one political "The world moves on" event. The player
   nation's `military` is set to `(current + 5)` (clamped) once per committed turn (not per item),
   the player is allied with the first other nation (by key order in the `nations` record), and the
-  date advances 2 days. Unit + e2e assertions rely on these exact values, so keep the stub
-  deterministic.
+  date advances 2 days. Since v0.21 the stub also makes **one contiguous conquest per turn**: the
+  player gains `frontier[0]` (the first of the sorted `frontier` list from the prompt payload —
+  stable) and that region's owner loses it; an empty frontier (no controllable border, e.g. the UK
+  in `wwii-1939`) transfers nothing. Since v0.22 (#16 P3) the stub **never releases** a region to
+  no man's land (it always returns `unowned: []` and ignores the payload's `unowned` field) — its
+  one-conquest behavior is what the e2e assertions rely on, so the release/re-claim path is
+  covered by unit tests only (`server/engine.test.ts`, `server/map.test.ts`). Since v0.23 (#16 P4a)
+  the stub also returns `nationOps: []` — it **never proposes** a nation op (rename/split/merge;
+  still true since P4b implemented split/merge), so the confirm/reject path is covered by unit
+  tests only, mirroring the P3 approach; all e2e assertions are unaffected. The stub answers plain `content` (never tool calls), so it naturally
+  bypasses the tool loop in a single round. Unit + e2e assertions rely on these exact values, so
+  keep the stub deterministic.
 - **HUD layout.** The game screen is a full-viewport map (z-0) with `FloatingWindow` overlays. The
   top bar is **pinned** — a fixed, non-movable bar centered at the top a few px down (it re-centers
   on resize and always floats above the other windows). The **dossier / event-feed / action**
@@ -208,6 +359,12 @@ history/
 > ignoring `reasoning`. `chat()` retries transient failures (timeout/abort, 5xx, network
 > errors, null/empty `content`) up to 3 attempts with 2s→3s backoff and logs every call
 > (`[llm] chat ok` / `[llm] chat failed`). No auth header is sent — the endpoint requires no key.
+> The same machinery backs `chatWithTools()` (the function-calling loop used by turns when the
+> region-adjacency manifest is loaded): a `finish_reason: "tool_calls"` response is a *successful*
+> round (never a truncation error), each requested tool call is run through the injected executor,
+> the assistant tool-call message plus one `tool` result message per call are appended to the
+> history, and the loop re-sends until a final `content` — max `DEFAULT_MAX_TOOL_ROUNDS = 6`
+> tool rounds, after which one last *no-tools* request forces the answer.
 | `PORT` | `4321` | single server port |
 | `DATA_DIR` | `./data` | where `history.db` lives |
 | `CLIENT_DIST` | `./dist` | built client to serve (auto-found) |
@@ -247,6 +404,11 @@ history/
   caught.
 - **`better-sqlite3`** is the only native module; the Docker build relies on its prebuilt binary
   (works on `node:22-slim`/glibc). It's the sole `--external` in the tsup server bundle.
-- The `dist/` client is committed to the build output only; the `public/` geo files
-  (`regions.geo.json` — the choropleth — and `countries.geo.json`) are copied into `dist/` by Vite
-  at build time, so the prod image serves them from `dist/` (no separate copy).
+- The `dist/` client is committed to the build output only; the `public/` data files
+  (`regions.geo.json` — the choropleth — `region-keys.json` + `region-adjacency.json` — the
+  ownership/adjacency manifests — `region-centroids.json` — the marker anchors (#44) — and
+   `countries.geo.json`) are copied into `dist/` by Vite at
+  build time, so the prod image serves them from `dist/` (no separate copy). The server's region
+  loader (`server/regions.ts`) probes `public/` then `dist/` for the manifest pair, because the
+  Docker image keeps only `dist/` (the v0.20 fix — before it, region-level ownership silently
+  never activated in prod).

CHANGELOG.md

@@ -2,6 +2,89 @@
 
 All notable changes to **History** are listed here, newest first.
 
+## v0.27.0 — 2026-10-14 22:34
+- **#44: the LLM can place named point markers on the map.** The model may now place up to a handful of named *point markers* per turn (a capital, city, factory complex, army deployment, port, fleet concentration, rocket launch site, or a political **gathering**), each anchored to a region key, persisted per game, and rendered on the choropleth as a MapLibre symbol layer.
+  - **Types (`shared/types.ts` + `shared/protocol.ts`).** Eight `MarkerType`s — `city, factory, army, port, capital, fleet, rocket, gathering` — with a shared `MARKER_TYPE_INFO` map (display label + color + glyph). A `MapMarker = { id, type, name, regionKey, lat, lon, ownerNationId, placedTurn }`; `GameState.markers: MapMarker[]` is **required** (`[]` at game creation, and a legacy SQLite row without the field loads as `[]` — additive, never wipes existing markers). `TurnResult.markers = { add: MarkerSpec[]; remove: string[] }` (both required, default `[]`); `MarkerSpec = { type, name, regionKey }`.
+  - **Stable ids (`shared/protocol.ts`).** A marker's `id` is the FNV-1a 32-bit hash of `` `${type}\u0000${name}\u0000${regionKey}` `` rendered as four lowercase base-26 characters (mirroring the region-key scheme). This makes a **re-add idempotent** (the same type+name+region never creates a second marker) and a **remove unambiguous** (by id).
+  - **Centroid data (`public/region-centroids.json`, new).** ~1,800 entries keyed identically to `region-keys.json`, each `{ lat, lon, spread }`: the anchor is the **centroid of the region's largest-area part** (a single representative point, not an average across disjoint parts), and `spread` ≈ **0.1 × that part's smallest bbox dimension** (in degrees). A new idempotent pipeline stage `scripts/build-region-centroids.mjs` (`npm run build:region-centroids`) regenerates it deterministically (byte-identical re-run, sha256-pinned by the test). The engine uses the centroid as the marker's base position and the `spread` to jitter multiple markers of one region around it (a deterministic per-axis FNV-1a-derived offset, so markers scatter instead of stacking).
+  - **Engine (`server/engine.ts`).** `applyTurnResult` processes markers **after** territory claims, in three steps: (1) remove by id (a listed-but-absent id is a no-op); (2) **recompute every surviving marker's `ownerNationId` from the final post-claim ownership** — a captured region follows its new owner, a region released to no man's land (or a key with 0 or 2+ owners) becomes `null` (a marker always follows its region); (3) add — each new spec is placed at its region's centroid (injected via a new optional `centroidOf` param) plus the per-axis jitter, owned by the region's post-turn owner, stamped with the acting turn. Adds are dropped (never thrown) when their region key is unknown / has no centroid, when the id already exists (idempotent re-add), or beyond the hard cap `MAX_MARKERS = 400` (later adds dropped). The system prompt documents the field, the eight types, and the placement rules; `buildUserPrompt` carries the current markers (as `MarkerInfo[]`) so the model can reference their stable ids in `remove`; `isMeaningful` treats a marker add/remove as a real world change.
+  - **Client (`src/components/WorldMap.tsx`).** A second GeoJSON source + a symbol layer sits above the choropleth. **Deliberate deviation from the original "name as a text label" design:** every external glyph endpoint is a dead 404 (OpenFreeMap's `fonts/{stack}/{range}.pbf` and `demotiles.maplibre.org/font/…`), and the OFM dark basemap only renders at all because it is **raster** (labels baked into the PNG tiles) — there is no working vector font. So markers are drawn as **self-contained, offline, canvas-generated per-type icons** (`drawMarkerIcon`: a distinct shape per type — circle / rounded-square / triangle / diamond / star / center-dotted circles / up-arrow — filled with the type color, outlined for legibility on the dark basemap), registered as named `ImageData` images that survive `styledata`. The marker **name is shown in the hover tooltip** (region name + owner chip + marker name) instead of a persistent on-map label, and **clicking a marker focuses its owning nation's dossier** (a marker's owner is its region's owner). There are no separate marker event handlers: MapLibre's per-layer event delegates fire independently (no `stopPropagation`), so the region hover/click handlers instead `queryRenderedFeatures` the marker layer under the cursor and act on the marker when present.
+  - **Stub (`server/stub.ts`) stays marker-free** — it returns `markers: { add: [], remove: [] }` — so the e2e suite (CI, `LLM_STUB=1`) is unaffected and fully deterministic; the full marker path is covered by unit tests only.
+- **Tests (168 → 189).** New `scripts/region-centroids.test.ts` (1,800 entries, key-set match, finite/world-bounds, each centroid inside its feature's bbox via turf-free coordinate iteration, spot-checked anchors, byte-identical re-run determinism); `server/regions.test.ts` (`hasCentroids`/`centroidOf` in dev + prod-`dist/` layouts, graceful degradation when absent); `server/db.test.ts` (legacy row → `markers: []`); and an `engine.test.ts` marker suite (valid add → id/position/owner/placedTurn, idempotent re-add, region-validity/centroid drops, the 400 cap, remove by id / no-op, owner-follows-region incl. release→null and re-claim, `buildUserPrompt`/system-prompt contract, `validateMarkerOps` raw cleaner, and the `runTurn` centroid wiring).
+- **Verification.** Typecheck, lint, **189 unit tests**, and the production build all pass (the build copies `region-centroids.json` into `dist/` like the other manifests, so it works in the prod container layout).
+- **Deploy:** manual `docker compose up -d --build` on the host — **no `down -v`** (markers are additive; legacy games load with `markers: []`).
+
+## v0.26.0 — 2026-10-14 19:24
+- **#41: the `RU-ARK` mainland's Arctic-coast band is re-coarsened into two new regions** — a pure re-partition of the existing polygon parts: no new geometry, no coordinate change (the feature union stays byte-identical). After #31 the mainland `RU-ARK` was a 33-part MultiPolygon; its 28-part band (parts whose centroid lat ≥ 68 — the Arctic-coast strip) is now split into:
+  - `RU-PEO` — Pechora (13 parts, ~37,678 km²) → new region key `pechora-qwhs`. The southwestern band (around the Pechora delta / Nenets border).
+  - `RU-YAM` — Yamal (15 parts, ~51,722 km²) → new region key `yamal-gosw`. The northeastern band (Yamal peninsula).
+  - The 5 remaining lat < 68 parts (the ~305,229 km² inland core) **stay `RU-ARK` and keep its id, name, and region key `arkhangel-sk-lhbk`** — ownership-safe, mirroring the #31 precedent. Splitting that core further requires geometry clipping (a turf-op), not a pure re-partition, and is left as a follow-up issue.
+  - **New pipeline stage** `scripts/split-arkhangel-band.mjs` (`npm run split:regions:band`), run between `split:regions` and `build:region-keys`: deterministic and **idempotent** (a second run is a no-op that writes nothing). It asserts the mainland is a 33-part MultiPolygon, selects the band as the 28 parts with centroid lat ≥ 68 (exactly 28, or it fails loudly), picks the two largest-area band parts as Voronoi anchors (the smaller-longitude one, `idx 1`, anchors the Pechora side), and assigns each band part to the nearer anchor by km-weighted centroid distance `hypot(Δlon·111.32·cos(midLat), Δlat·110.574)` (ties go west). The resulting partition is exactly PEO={1,4,5,9,11,12,13,14,16,17,18,20,22}, YAM={2,6,15,19,21,23,24,25,26,27,28,29,30,31,32}, core={0,3,7,8,10}. The two new features are inserted **immediately after `RU-ARK-SZ`** (stable file order: `RU-ARK` | `RU-ARK-NE` | `RU-ARK-SZ` | `RU-PEO` | `RU-YAM` | `RU-AST` | …).
+  - **Manifests regenerated** with the real scripts and remain deterministic/idempotent (byte-identical re-run): `public/region-keys.json` and `public/region-adjacency.json` are now **1,800 entries each** (was 1,798); adjacency pairs 4,471 → 4,473. The new pairs are `pechora-qwhs ↔ yamal-gosw`, `pechora-qwhs ↔ nenets-qyga`, and `yamal-gosw ↔ severnaya-zemlya-awqp`, while the mainland `arkhangel-sk-lhbk` **loses** its `severnaya-zemlya-awqp` pair (the islets now touch the Yamal band, not the inland core) and keeps its six real neighbours (`karelia-ohem`, `kirov-gfvm`, `komi-eoeh`, `murmansk-etas`, `nenets-qyga`, `vologda-ynvr`). `new-earth-eikt` stays isolated (empty adjacency).
+  - **Fixed-point dataset unchanged except feature count** (1,798 → 1,800): the part/ring/vertex totals (11,794 / 11,795 / 164,801) and the single hole (KZ-KZY) are identical before and after — only the feature grouping changes. The RU-ARK family total stays 78 parts (mainland 5 / NE 42 / SZ 3 / PEO 13 / YAM 15).
+  - **Tests (168, count unchanged — existing cases updated, none added).** `scripts/regions.test.ts` (dataset is now 1,800 features; the Arkhangel feature-pin test now covers all five family members), `scripts/region-keys.test.ts` (1,800 keys; pins the unchanged `arkhangel-sk-lhbk` plus the two new keys), `scripts/region-adjacency.test.ts` (1,800 entries; pins the new PEO/YAM/SZ adjacency and the mainland's loss of the SZ pair), `server/regions.test.ts` (1,800; the RUS country expansion is now **84** sub-regions including all five keys — was 82 after #31). No e2e assertion references the region counts, so the CI e2e suite is unaffected.
+  - **LLM/engine/stub unchanged.** At game creation RUS simply auto-owns the two extra band regions (82 → 84 sub-regions); the LLM's reference table and the player's frontier now include `pechora-qwhs` and `yamal-gosw`.
+  - Deployed to `https://history.dev.kkhost.pl` with the authorized **clean data wipe** (`docker compose down -v` → `up -d --build`; the alpha `history-data` volume was destroyed, resetting all saved games).
+
+## v0.25.0 — 2026-10-14 17:53
+- **#31: the `RU-ARK` mega-region is split into a mainland region plus two island groups** — a pure re-grouping of the existing polygon parts: no new geometry, no coordinate changes. The old single feature (Arkhangel'sk Oblast + the Arctic archipelagos, 78 parts, ~410,187 km²) becomes three features inserted immediately after `RU-ARK` (stable file order: `RU-ARK` | `RU-ARK-NE` | `RU-ARK-SZ` | `RU-AST`):
+  - `RU-ARK` — the mainland (33 parts, ~393,256 km²); it **keeps its existing id and region key `arkhangel-sk-lhbk`**, so existing `Nation.territory` lists and SQLite ownership are untouched (ownership-safe).
+  - `RU-ARK-NE` — New Earth / Franz Josef Land (42 parts, ~15,721 km²) → new region key `new-earth-eikt`. Genuinely isolated (≥100 km from any land), so its adjacency list is **empty**.
+  - `RU-ARK-SZ` — Severnaya Zemlya (3 parts, ~1,210 km²) → new region key `severnaya-zemlya-awqp`. Its islet rings share boundary vertices with the coarsened mainland ring (a contact that pre-existed inside the single pre-split feature — no coordinate change), so it records **one** adjacency pair (SZ ↔ `arkhangel-sk-lhbk`). This deviates from the original "both islands isolated" expectation and is recorded as-is by the manifest's "shares at least one point" definition.
+  - **New pipeline stage** `scripts/split-arkhangel.mjs` (`npm run split:regions`), run between `fill:regions` and `build:region-keys`: deterministic and **idempotent** (a second run is a no-op that writes nothing). It classifies each part by centroid (turf — allowed in `.mjs` only): main = lat < 76 (plus any 76–79.5° band parts west of 55°E — none exist), Severnaya Zemlya = 76 ≤ lat < 79.5 AND lon ≥ 55, New Earth = lat ≥ 79.5. It fails loudly on a mis-split, a missing feature, or a non-MultiPolygon geometry.
+  - **Manifests regenerated** with the real scripts and remain deterministic/idempotent (byte-identical re-run): `public/region-keys.json` and `public/region-adjacency.json` are now **1,798 entries each** (was 1,796); adjacency pairs 4,470 → 4,471 (the one new pair is the SZ ↔ mainland contact; the mainland keeps its 6 real neighbours).
+  - **Fixed-point dataset unchanged except feature count** (1,796 → 1,798): the part/ring/vertex totals (11,794 / 11,795 / 164,801) and the single hole (KZ-KZY) are identical before and after the split.
+  - **Tests (164 → 168).** `scripts/regions.test.ts` (dataset is now 1,798 features; a new test pins the three Arkhangel features and their part counts), `scripts/region-keys.test.ts` (1,798 keys; a new test pins the unchanged main key plus the two new keys), `scripts/region-adjacency.test.ts` (1,798 entries; a new island-adjacency test: New Earth empty, Severnaya Zemlya = [mainland], mainland's neighbour list extended by exactly the SZ pair), `server/regions.test.ts` (1,798; the RUS country expansion is now **82** sub-regions including all three keys — was 80). No e2e assertion references the old counts, so the CI e2e suite is unaffected.
+  - **LLM/engine/stub unchanged.** At game creation RUS simply auto-owns the two extra island regions (80 → 82 sub-regions).
+  - Deployed to `https://history.dev.kkhost.pl` with the authorized **clean data wipe** (`docker compose down -v` → `up -d --build`; the alpha `history-data` volume was destroyed, resetting all saved games).
+
+## v0.24.0 — 2026-10-14 13:41
+- **Part 4b of #16: nation splits and merges — "LLM proposes, player confirms" is now complete.** P4a let the LLM propose a *rename* (a safe, single-field change). Now the same confirm/reject flow actually applies the two destructive ops: a **split** (one nation dissolves into several) and a **merge** (several nations fold into one). This is the last piece of #16 — all three `NationOp` kinds are now applied on player confirm.
+  - **Split (`server/engine.ts`).** `applyNationOp` now handles `kind: "split"`: it resolves the parent `nationRef` and requires **≥2** named parts (fewer → a safe no-op, the op is still resolved and removed). It partitions the parent's **region-key** territory across the parts **in order** — each part gets the keys of its `territory` that the parent actually owns and that no earlier part claimed (the **first part to name a key wins**, so a key is never held twice); any of the parent's keys no part claimed go to **part 0** (in the parent's territory order), so nothing is orphaned. Each new nation gets a **fresh id** (`freshNationId`: first free of `n1`, `n2`, …, tracked in a running `taken` set so ids never collide within the op), the baseline `NEW_NATION_STATS` (a neutral 50/50/50/50 profile — *not* a copy of the parent's, since a small rump state is not the parent's power), a copy of the parent's relations, and the parent's `type`; the parent is then removed and its id dropped from every other nation's relations map (`dropRelationsTo`). If the **parent was the player's nation**, `playerNationId` moves to the chosen part (`edits.playerPart`, clamped into range, default 0) — that same part also receives an `edits.name` override.
+  - **Merge (`server/engine.ts`).** `kind: "merge"`: every input ref and the survivor ref must resolve, at least **two distinct** inputs are required, and the **survivor must be one of the inputs** — any failure is a safe no-op. The survivor keeps its **id** and its **own stats**; it gains the **union of all inputs' territories** (the survivor's keys first, then each other input's unclaimed keys in its own order) and a **union of the inputs' relations** (the survivor's own view of a third party wins, else the first input's); it is renamed to `edits.name` → `into` → its own name (in that precedence). The other inputs are removed and their ids dropped from every remaining nation's relations maps; if the **player led a removed input**, `playerNationId` moves to the survivor.
+  - **Confirm contract extended (`shared/protocol.ts`).** `ConfirmNationOpRequest.edits` is now `{ name?: string; playerPart?: number }` — `name` overrides a rename's target or a merge's merged name; `playerPart` picks which new part the player's nation becomes in a split (default 0). The `SplitOp` / `MergeOp` / `NationOp` doc comments and the `TurnResult.nationOps` doc now describe the *applied* semantics (no longer "a no-op until P4b").
+  - **Prompt (`server/engine.ts`).** The system prompt's JSON contract now shows all three `nationOps` shapes (rename / split / merge), and the HARD CONSTRAINTS gain one line per op explaining when to use it and the "≥2 parts" / "survivor must be an input" rules — so the model knows what it may propose and that each is a player-confirmed PROPOSAL.
+  - **Client (`src/components/NationOpDialog.tsx`).** The dialog now renders all three kinds with a Confirm button (no more "dismiss-only" split/merge rows): a **split** lists each part (name + the number of regions it was assigned) and, when the split's parent is the **player's own nation**, shows a **radio group** to pick which new part the player leads (preselected 0, so the choice is always valid); a **merge** shows the input nations as chips (the **survivor** highlighted) and an **editable name** for the merged state (defaulting to `into`). Rename keeps its editable-name behavior. The new `onConfirm(index, edits?)` signature threads `playerPart` through `ActionPanel` and `App.tsx` (`runConfirmNationOp`) to the API helper.
+  - **Defensive invariants.** All ops are **pure and never throw**: an unresolvable or ambiguous ref, too few parts, or a survivor that isn't an input makes the op a no-op on the world (the proposal is still resolved and removed on confirm, mirroring P4a's ambiguous-ref behavior). **Sole ownership** is preserved by construction (a key lands in at most one new part / one survivor), and `playerNationId` is always re-pointed to a still-existing nation. The **stub is unchanged** — it still never proposes a nation op (`nationOps: []`) — so, like P4a/P4b before it, the new paths are covered by **unit tests only** and the e2e suite (CI, `LLM_STUB=1`) is unaffected.
+- **Tests (`server/engine.test.ts`).** New `freshNationId`, `applyNationOp (split)`, and `applyNationOp (merge)` suites: the partition (first-wins, leftovers-to-part-0, sole ownership, fresh ids/stats/relations, parent removed, relations cleanup, player-pointer move, clamped `playerPart`, `edits.name` on the chosen part), the merge (union territory, survivor stats, relations union with survivor-wins, removed ids dropped from everyone else, into-name, player-pointer move, and the four no-op guards), plus an updated prompt-contract test asserting all three op shapes. The old "split/merge is a no-op" P4a test is retargeted to a 1-part split. The unit suite grows **151 → 164**.
+- **Verification.** Typecheck, lint, **164 unit tests**, and the production build all pass. The e2e suite (CI, `LLM_STUB=1`) carries no nation-op assertions, so it stays green with the unchanged stub.
+- **Deploy:** manual `docker compose up -d --build` on the host (no `down -v`).
+- Part of #16 — major nation changes (P4b, the final part of the epic). #16 was already closed (2026-10-12, after P3 shipped); the PR references it for traceability the same way P4a's PR #38 did ("Part of #16" / "Related: #16") — no auto-close.
+
+## v0.23.0 — 2026-10-14 12:58
+- **Part 4a of #16: nation renames — "LLM proposes, player confirms."** The LLM can now propose that a nation be renamed during a turn. Unlike stat/relation/territory changes (applied automatically), a rename is stored as a **pending proposal** (`GameState.pendingNationOps`) and only takes effect when the player **confirms** it (optionally editing the new name) or is dropped on **reject**. This is the first of the "major nation changes" the LLM may propose — the `NationOp` contract is stable now; **split** and **merge** are declared in the same union but are *accepted-and-stored, not applied* until P4b.
+  - **New `NationOp` union (`shared/protocol.ts`).** `rename` / `split` / `merge`, discriminated by `kind`. Each names its target via a `nationRef` the LLM may give as either a nation **id** or **name**. `TurnResult.nationOps` is a **required** `NationOp[]` (the model's proposals this turn); the confirm/reject request types (`NationOpConfirmRequest` `{index, edits?{name?}}`, `NationOpRejectRequest` `{index}`, response `{game}`) live here too.
+  - **`GameState.pendingNationOps` (`shared/types.ts`, type-only import of `NationOp`)** — the proposals awaiting the player's decision. A turn **appends** to it (never clears it on commit), so a proposal persists across turns until confirmed or rejected. Legacy SQLite rows and new games default it to `[]` (`server/db.ts`).
+  - **Engine (`server/engine.ts`), all pure.** `resolveNationRef` resolves a `nationRef` id-first, then a case-insensitive unique-name match (returns `null` for unknown/ambiguous — never throws). `validateNationOps` drops invalid ops defensively. `applyTurnResult` keeps existing pending ops and appends the turn's valid ones (a rename-only turn is `isMeaningful`, so it survives the retry/nudge path). `applyNationOp` mutates a clone (rename → `Nation.name` = edited value or the proposed `to`; split/merge are no-ops for now). `confirmNationOp`/`rejectNationOp` splice by index and bump `version` once (invalid index → `null`). The system prompt (both tool-mode and plain-mode) gains the `nationOps` JSON field and the rename-proposal rule.
+  - **Routes + client.** `POST /api/games/:id/nation-op/confirm` and `.../reject` (404 unknown game, 400 bad index), each returning `{ game }` and broadcasting a version-bumped SSE `state` — mirroring the existing queue add/remove routes. The "Your move" panel shows a "Nation proposals (N)" trigger that opens a dialog listing each pending op; a rename has an editable name field plus **Confirm**/**Reject**, and split/merge offer **Dismiss** (they aren't applied yet).
+  - **Stub + tests.** The deterministic stub **never** proposes a nation op (`nationOps: []`), so this path is covered by **unit tests only** (mirroring the P3 no-man's-land approach) — `server/engine.test.ts` gains suites for `resolveNationRef`, `validateNationOps`, `applyNationOp`/confirm/reject (incl. an invalid-index 400 and the version-bump), and the prompt contract. The unit suite grows **127 → 151**; the e2e suite is unaffected.
+- **Verification.** Typecheck, lint, **151 unit tests**, and the production build all pass. The e2e suite (CI, `LLM_STUB=1`) has no nation-op assertions, so it stays green with the unchanged stub.
+- **Deploy:** manual `docker compose up -d --build` on the host (no `down -v`).
+- Part of #16 — major nation changes (P4a); #16 stays open (P4b: split/merge).
+
+## v0.22.0 — 2026-10-14 12:02
+- **Part 3 of #16: no man's land — a region can be left unowned mid-game and re-claimed later.** After a war or cataclysm the LLM can leave a region without an owner: it lists the key in the new `TurnResult.unowned` field (and narrates the cause in `events`); the engine removes the key from its sole owner, and the region ends the turn ownerless. A later ordinary `gain` on that key is a **re-claim** — the key is granted to the (sole) gainer and removed from the no-man's-land list. A fresh game always starts fully owned (no man's land can only arise mid-game).
+  - **Engine (`server/engine.ts`).** `applyTurnResult` applies **releases first**: a key is released only when it has exactly one current owner (0 owners — a preset never assigned it — is a no-op, so no man's land can never be fabricated from an ordinary unowned region; 2+ owners — corruption — is a no-op; already-unowned is a no-op). Claims are then resolved against the post-release ownership snapshot: sole gainer + sole owner ≠ gainer = a transfer (the v0.21 rules, unchanged); sole gainer + no owner = a re-claim; a double claim is still rejected. Invariants after every turn: no key sits in two or more territories, a released key sits in none, and `GameState.unowned` holds exactly the keys released mid-game. A lone release counts as `isMeaningful` (it survives the retry/nudge path instead of being replaced by the generic "unclear" result). The system prompt gains the JSON field, the no-man's-land rule (in both tool-mode and plain-mode), and the hard constraint that `unowned` may contain only region keys a nation currently owns. The user payload always carries the current `GameState.unowned` as `unowned` (even when empty), and the jump route's `regions` reference table now includes the released keys so the model can name them when re-claiming.
+  - **New required `GameState.unowned` field** (`shared/types.ts`): the cumulative list of keys released mid-game. A no-man's-land region is **distinct from a preset-unassigned region** — the presets assign only ~25–30% of the 1,796 sub-regions (e.g. `wwii-1939` starts with 411 owned / 1,385 unowned), so ~1,300 ownerless regions exist at init; those keep the existing faint look, and only `GameState.unowned` keys get the distinct one. Legacy SQLite rows saved before v0.22 load with the field defaulted to `[]` (`server/db.ts`), and game creation sets it to `[]`.
+  - **Map presentation (a new contract in `shared/protocol.ts`).** `regionFillStyle(owner, isNoMansLand)` + `unownedTooltipLabel` decide the look: an owned region is unchanged (nation color + `OWNED_STROKE`); a released region gets the distinct visible grey `NO_MANS_LAND_FILL = '#3f3f46'` (hue-less by construction, so it can never collide with a nation's `hsl(h 58% 46%)` color) with a brighter border (`NO_MANS_LAND_STROKE`) and the tooltip sub-line "No man's land"; every other ownerless region keeps the faint `rgba(148,163,184,0.05)` fill and "No owner". The client (`WorldMap`, via a new `unowned` prop from `App.tsx`) is the sole consumer of the distinction — the `RegionMap` simply has no entry for an unowned key (`buildRegionMap` is unchanged). Clicking a no-man's-land region does not change the dossier (there is no owner to focus), and a release/re-claim flashes like any other ownership change.
+  - **Stub + tests.** The deterministic stub is deliberately **unchanged** — it never releases a region (it always returns `unowned: []` and ignores the payload's `unowned` field), because its one-conquest behavior is what the e2e assertions rely on; the release/re-claim path is therefore covered by **unit tests only** (a new `applyTurnResult (no man's land)` suite: release, re-claim, release+claim of the same key, a double claim on a released key, the four no-op release cases, a legacy state without the field, and a `runTurn` end-to-end test with a narrated release; new `buildUserPrompt`/`buildSystemPrompt` contract tests; a presentation-contract suite in `server/map.test.ts`; a legacy-row normalization test in `server/db.test.ts`). The unit suite grows **105 → 127**.
+  - **No data-format wipe.** The `GameState` shape only gains a field that legacy rows load with, so existing saves remain compatible: the deploy is a plain `up -d --build` (no `down -v`).
+- **Verification.** Typecheck, lint, **127 unit tests**, and the production build all pass. The e2e suite (CI, `LLM_STUB=1`) carries no map-color/no-man's-land assertions, so it stays green with the unchanged stub.
+- **Deploy:** manual `docker compose up -d --build` on the host (no `down -v`).
+- Part of #16 — no man's land (P3); #16 stays open.
+
+## v0.21.0 — 2026-10-14 10:37
+- **Part 2 of #16: territory now moves region-by-region along real land borders, and the LLM can verify borders with a live tool.** v0.19 made ownership region-keyed, but the model's `territoryChanges` were still applied wholesale — any key could jump to any nation, effectively moving whole countries. Now:
+  - **Region-adjacency manifest (Stage 1).** `scripts/build-region-adjacency.mjs` (`npm run build:region-adjacency`) computes which of the 1,796 sub-regions share a land border: per candidate pair, a cheap bbox-proximity prefilter (0.05° gap reject) then a `@turf/boolean-intersects` arbiter. The output `public/region-adjacency.json` is symmetric and deduped — **1,796 entries, 4,470 border pairs (8,940 directed), max degree 19; 1,727 regions have ≥1 neighbour, 69 don't** — and is deterministic/idempotent (sha256 `e9f1d475…`; re-running is byte-identical). Vite copies it into `dist/` for prod; `server/regions.ts` loads it (turf-free — plain `JSON.parse`, no `@turf` import in any `.ts`) and degrades gracefully when it is missing.
+  - **`getNeighbours` LLM tool (Stage 2).** `server/llm.ts` gains `LlmClient.chatWithTools` — a bounded OpenAI function-calling loop: on a `finish_reason: "tool_calls"` response the client runs the injected executor for every call, appends the assistant tool-call message plus one `tool` result message per call, and re-sends until a final `content` (max **6** tool rounds, then one last *no-tools* request forces the answer). It shares the retry/backoff/`reasoning_effort: "low"` machinery with `chat()`; a tool-call round is a success (never treated as truncation); malformed tool arguments become an `{"error":"invalid tool arguments…"}` tool message, so a bad model reply can never throw. `tools` is included in the request body only when non-empty, so plain `chat()` bodies (and their tests) are unchanged.
+  - **Engine wiring.** `runTurn` takes an optional `getNeighbours` resolver — the server's jump route passes one only when the manifest loaded (`hasAdjacency()`). With both the resolver and a `chatWithTools`-capable client, the turn runs the tool path: the system prompt gains the contiguity rules (a nation may only GAIN a key that borders its own territory; every key has exactly one owner) and advertises the tool; the user payload gains a `frontier` field — the player's `playerFrontier`, the sorted/deduped set of *other-nation* keys bordering the player's territory (the natural targets of a player-led conquest). Without the manifest, or with a minimal chat-only client, the turn falls back to the legacy plain `chat()` path — everything keeps working, the tool/frontier simply switch off.
+  - **Sole-ownership enforcement.** `applyTurnResult` now applies territory snapshot-first: before mutating anything it computes each key's current owner, and a key transfers only when (a) exactly one nation claims to gain it (a double claim is rejected — the key stays), (b) it has exactly one current owner (pre-existing double ownership is never touched), and (c) the owner is not the gainer (self-gain is a no-op). A transfer removes the key from all nations first, then grants it to the gainer; lone `lose` entries are no-ops. Every key therefore ends the turn with exactly one owner — it can never be orphaned or duplicated, and a bad model answer degrades to "no transfer", never to a corrupt map.
+  - **Deterministic stub.** The stub now makes one contiguous conquest per turn: the player gains `frontier[0]` (sorted → stable) and its owner loses it. It answers plain content (no tool calls), so it naturally bypasses the tool loop in a single round; with an empty frontier (no controllable border — e.g. the UK in `wwii-1939`, whose only external neighbour is Ireland) nothing transfers and every existing e2e assertion stays stable.
+  - **No data-format change — no save wipe.** The `TerritoryChange` wire shape is unchanged and saved games load as-is, so the deploy is a plain rebuild (no `down -v`).
+- **Verification.** Typecheck, lint, **105 unit tests** (79 baseline + 26 new: tool-loop protocol — echo, parsed executor args, bounded rounds, malformed args, retry; engine tool-path wiring + fallback; `playerFrontier`; executor degradation; sole-ownership invariants; `neighboursOf`/`hasAdjacency`), the production build, and all **14 e2e** tests pass.
+- **Deploy:** manual `docker compose up -d --build` on the host (no `down -v`).
+- Part of #16 — P3 (region rename/split/merge) and P4 follow; #16 stays open.
+
 ## v0.20.0 — 2026-10-14 09:30
 - **Fixed: v0.19.0's region-level ownership did not activate in the production image.** The server-side region loader (`server/regions.ts`) only looked for the manifest + geo in `public/`, but in the Docker image Vite copies `public/*` → `dist/` and no `public/` directory is kept — so `loadRegions` found nothing, `expandCountriesToKeys` degraded to a no-op, and freshly-created games kept raw ISO_A3 codes (`DEU`, `GBR,IRL,IND`, …) instead of expanding to region keys. The choropleth therefore still rendered whole-country ownership and the model's region-key contract was inactive in prod (the client's own `/region-keys.json` fetch still worked, because the client is served from `dist/`). `loadRegions` now probes `public/` (dev) then `dist/` (prod, == `clientDir`) and uses the first directory holding both files, so one build works in both environments. A new test covers the prod-only (`dist/`), dev (`public/`), and empty-root (no data) layouts.
 - **Deploy:** `docker compose down -v` (drops the `history-data` volume — pre-v0.19 saves were already dropped by v0.19.0 and are dropped again here) then `up -d --build`.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "history",
-  "version": "0.20.0",
+  "version": "0.27.0",
   "private": true,
   "type": "module",
   "description": "AI-driven alternate-history simulator — the LLM is the world engine (Pax Historia style).",
@@ -14,7 +14,11 @@
     "cleanup:regions": "node scripts/cleanup-regions.mjs",
     "smooth:regions": "node scripts/smooth-regions.mjs",
     "fill:regions": "node scripts/fill-gaps.mjs",
+    "split:regions": "node scripts/split-arkhangel.mjs",
+    "split:regions:band": "node scripts/split-arkhangel-band.mjs",
     "build:region-keys": "node scripts/build-region-keys.mjs",
+    "build:region-adjacency": "node scripts/build-region-adjacency.mjs",
+    "build:region-centroids": "node scripts/build-region-centroids.mjs",
     "typecheck": "tsc --noEmit",
     "lint": "eslint .",
     "e2e": "playwright test"

public/region-keys.json

@@ -1305,6 +1305,10 @@
   "RU-ALT": "altay-mfuq",
   "RU-AMU": "amur-clbp",
   "RU-ARK": "arkhangel-sk-lhbk",
+  "RU-ARK-NE": "new-earth-eikt",
+  "RU-ARK-SZ": "severnaya-zemlya-awqp",
+  "RU-PEO": "pechora-qwhs",
+  "RU-YAM": "yamal-gosw",
   "RU-AST": "astrakhan-anec",
   "RU-BA": "bashkortostan-uovk",
   "RU-BEL": "belgorod-wxjk",

scripts/build-region-adjacency.mjs

@@ -0,0 +1,133 @@
+/**
+ * scripts/build-region-adjacency.mjs — build the precomputed region-adjacency
+ * manifest: `public/region-adjacency.json` = `{ "<regionKey>": ["<neighbourKey>", ...], ... }`.
+ *
+ * For every sub-region (region key, see `public/region-keys.json`) this records
+ * which *other* sub-regions it **borders** — i.e. shares an edge or a point with.
+ * The result is the data behind the model's `getNeighbours` tool (P2 of #16):
+ * given a set of region keys, the engine returns the union of their adjacency
+ * entries (excluding the queried keys), so the LLM can plan *frontier-biased,
+ * contiguous* territory transfers (a nation realistically gains/loses a region
+ * it already abuts) instead of whole countries.
+ *
+ * Method — bounding-box-pruned polygon intersection (turf is allowed in .mjs
+ * scripts; it is deliberately kept OUT of the TS typecheck program, see the
+ * v0.17 note). For each unordered pair of regions (i < j) we first do a cheap
+ * bbox-proximity reject with a small gap tolerance (adjacent regions' bboxes
+ * touch, so their gap is ≈0), and only for the survivors do we run
+ * `@turf/boolean-intersects`, which returns true exactly when the two
+ * (Multi)Polygons share at least one point (edge or corner touch, or overlap).
+ * A hit adds each key to the other's set — adjacency is recorded **symmetrically**
+ * and **deduplicated** (a neighbour appears once even if the pair shares several
+ * disjoint border segments).
+ *
+ * Output contract (asserted by scripts/region-adjacency.test.ts):
+ *   - one entry for **every** region key (including regions with no bordering
+ *     neighbours, e.g. isolated islands — their list is simply empty);
+ *   - adjacency is symmetric (A ∈ B's list  ⟺  B ∈ A's list);
+ *   - no key lists itself.
+ *
+ * Deterministic + idempotent: the input files are fixed, the intersection test
+ * is a pure geometric computation, and the output is written with keys and
+ * neighbour lists both sorted — so a re-run rewrites a byte-identical file.
+ *
+ * Usage: `node scripts/build-region-adjacency.mjs`  (or `npm run build:region-adjacency`).
+ */
+import { readFileSync, writeFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import bbox from '@turf/bbox';
+import booleanIntersects from '@turf/boolean-intersects';
+import { feature } from '@turf/helpers';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+
+// "Close enough" bbox gap (degrees) for the cheap reject. Adjacent regions'
+// bboxes touch (gap ≈ 0); a small tolerance absorbs 4-dp coordinate rounding
+// and digitization fuzz. It only prunes work — it never affects correctness,
+// because `booleanIntersects` is the final arbiter (a pair is a neighbour only
+// if the polygons actually share a point).
+const GAP_DEG = 0.05; // ≈ 5.5 km
+
+// --- load the geo + region-key manifest (plain parse; keys join feature->key) --
+const geo = JSON.parse(readFileSync(path.join(root, 'public', 'regions.geo.json'), 'utf8'));
+const idToKey = JSON.parse(readFileSync(path.join(root, 'public', 'region-keys.json'), 'utf8'));
+
+// Region records in stable file order, keyed by their region key.
+const regions = [];
+for (const f of geo.features ?? []) {
+  const id = f.id == null ? '' : String(f.id);
+  const key = idToKey[id];
+  if (!key) continue; // a geo feature with no manifest entry is skipped
+  regions.push({ key, feature: feature(f.geometry), bbox: bbox(f.geometry) });
+}
+
+if (regions.length === 0) {
+  throw new Error('no regions with valid region keys — check regions.geo.json / region-keys.json');
+}
+
+// bboxes are flat [minX, minY, maxX, maxY] (turf's BBox type).
+function bboxesClose(a, b) {
+  return (
+    a[0] <= b[2] + GAP_DEG && // a.w <= b.e + gap
+    b[0] <= a[2] + GAP_DEG && // b.w <= a.e + gap
+    a[1] <= b[3] + GAP_DEG && // a.s <= b.n + gap
+    b[1] <= a[3] + GAP_DEG // b.s <= a.n + gap
+  );
+}
+
+// key -> set of neighbouring keys (deduped; a pair sharing several segments is
+// recorded once).
+const adj = new Map();
+for (const r of regions) adj.set(r.key, new Set());
+
+let pairChecks = 0;
+let intersections = 0;
+for (let i = 0; i < regions.length; i++) {
+  for (let j = i + 1; j < regions.length; j++) {
+    if (!bboxesClose(regions[i].bbox, regions[j].bbox)) continue; // cheap reject
+    pairChecks++;
+    let touches = false;
+    try {
+      touches = booleanIntersects(regions[i].feature, regions[j].feature);
+    } catch {
+      touches = false; // a degenerate geometry pair is treated as non-adjacent
+    }
+    if (touches) {
+      intersections++;
+      adj.get(regions[i].key).add(regions[j].key);
+      adj.get(regions[j].key).add(regions[i].key);
+    }
+  }
+}
+
+// --- write idempotently: keys sorted, neighbour lists sorted ------------------
+// Every region key gets an entry (an isolated island's list is simply empty).
+const manifest = {};
+for (const key of [...adj.keys()].sort()) {
+  manifest[key] = [...adj.get(key)].sort();
+}
+
+// Self-reference guard (can't happen — we only ever add the *other* region — but
+// assert it so a future regression is loud rather than silent).
+for (const [k, list] of Object.entries(manifest)) {
+  if (list.includes(k)) throw new Error(`region ${k} lists itself as a neighbour`);
+}
+
+writeFileSync(path.join(root, 'public', 'region-adjacency.json'), JSON.stringify(manifest, null, 2) + '\n');
+
+// --- summary ------------------------------------------------------------------
+const totalEntries = Object.values(manifest).reduce((n, l) => n + l.length, 0);
+const withNeighbours = Object.values(manifest).filter((l) => l.length > 0).length;
+const maxDegree = Math.max(0, ...Object.values(manifest).map((l) => l.length));
+console.log(
+  `[build-region-adjacency] wrote public/region-adjacency.json — ${Object.keys(manifest).length} region keys, ` +
+    `${totalEntries / 2} border pairs (${totalEntries} directed entries), max degree ${maxDegree}, ` +
+    `${withNeighbours} with ≥1 neighbour (${pairChecks} bbox-close pairs tested, ${intersections} intersect)`,
+);
+// A couple of human-checkable examples (highest-degree regions, stable order).
+const byDegree = Object.entries(manifest).sort((a, b) => b[1].length - a[1].length || a[0].localeCompare(b[0]));
+for (const [k, list] of byDegree.slice(0, 3)) {
+  console.log(`  e.g. ${k} (deg ${list.length}) → ${list.slice(0, 4).join(', ')}${list.length > 4 ? ', …' : ''}`);
+}

scripts/build-region-centroids.mjs

@@ -0,0 +1,132 @@
+/**
+ * scripts/build-region-centroids.mjs — build the precomputed region-centroid
+ * manifest: `public/region-centroids.json` = `{ "<regionKey>": { "lat": <number>, "lon": <number>, "spread": <number> }, ... }`.
+ *
+ * For every sub-region (region key, see `public/region-keys.json`) this records
+ * the point the LLM's map markers (v0.27, #44) will be anchored to: the
+ * **centroid of the region's largest-area part** (a MultiPolygon's biggest
+ * island/lake-piece rather than an area-weighted average of all parts), plus
+ * a `spread` value ≈ 0.1 × the smallest bbox dimension of that part (in
+ * degrees) — the engine scatters markers of one region within ±(spread/2)
+ * around the centroid using a deterministic per-marker offset, so several
+ * markers of the same region do not stack on one pixel.
+ *
+ * Method — plain turf on the pre-generated geo file (turf is allowed in .mjs
+ * scripts; it is deliberately kept OUT of the TS typecheck program, see the
+ * v0.17 note). For each feature we (1) split a MultiPolygon into its parts
+ * (a plain Polygon is its own single part), (2) pick the part with the
+ * greatest `@turf/area`, (3) take `@turf/centroid` of that part and
+ * `@turf/bbox` of that part, and (4) round everything to 6 decimal places
+ * (≈ 0.1 m at this scale — far below the map's visual precision).
+ *
+ * Output contract (asserted by scripts/region-centroids.test.ts):
+ *   - one entry for **every** region key, keyed identically to
+ *     `public/region-keys.json` (same key set, 1,800 entries);
+ *   - each centroid lies inside its region's (largest part's) bbox;
+ *   - `spread` is a non-negative number of degrees (0 for degenerate parts);
+ *   - values are rounded to at most 6 decimal places.
+ *
+ * Deterministic + idempotent: the input files are fixed, turf is a pure
+ * geometric computation, the output keeps the geo file's (stable) feature
+ * order and rounds to fixed precision — so a re-run rewrites a byte-identical
+ * file (the test re-runs this script and compares bytes).
+ *
+ * Usage: `node scripts/build-region-centroids.mjs`  (or `npm run build:region-centroids`).
+ */
+import { readFileSync, writeFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import area from '@turf/area';
+import bbox from '@turf/bbox';
+import centroid from '@turf/centroid';
+import { feature } from '@turf/helpers';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+
+const round6 = (v) => Math.round(v * 1e6) / 1e6;
+
+// --- load the geo + region-key manifest (plain parse; keys join feature->key) --
+const geo = JSON.parse(readFileSync(path.join(root, 'public', 'regions.geo.json'), 'utf8'));
+const idToKey = JSON.parse(readFileSync(path.join(root, 'public', 'region-keys.json'), 'utf8'));
+
+/**
+ * The polygon parts of a geometry: a MultiPolygon's individual polygons, a
+ * plain Polygon as its own single part, anything else as an empty list (the
+ * caller falls back to the whole-feature centroid).
+ */
+function partsOf(geometry) {
+  if (geometry?.type === 'MultiPolygon') return geometry.coordinates ?? [];
+  if (geometry?.type === 'Polygon') return [geometry.coordinates];
+  return [];
+}
+
+const manifest = {};
+let skipped = 0;
+for (const f of geo.features ?? []) {
+  const id = f.id == null ? '' : String(f.id);
+  const key = idToKey[id];
+  if (!key) continue; // a geo feature with no manifest entry is skipped
+  const parts = partsOf(f.geometry);
+  if (parts.length === 0) {
+    // Degenerate geometry (a point/line region): anchor at the feature's own
+    // centroid. Can't happen with the current 1,800-polygon dataset, but the
+    // fallback keeps the manifest complete if the generator ever changes.
+    skipped += 1;
+    const c = centroid(feature(f.geometry));
+    const b = bbox(feature(f.geometry));
+    manifest[key] = {
+      lat: round6(c.geometry.coordinates[1]),
+      lon: round6(c.geometry.coordinates[0]),
+      spread: round6(Math.min(b[2] - b[0], b[3] - b[1]) * 0.1),
+    };
+    continue;
+  }
+  // Pick the part with the greatest area (km²) and anchor to IT, so a
+  // multi-part region's markers cluster on its main mass, not between parts.
+  let best = 0;
+  let bestArea = -1;
+  for (let i = 0; i < parts.length; i++) {
+    const a = area(feature({ type: 'Polygon', coordinates: parts[i] }));
+    if (a > bestArea) {
+      bestArea = a;
+      best = i;
+    }
+  }
+  const part = feature({ type: 'Polygon', coordinates: parts[best] });
+  const c = centroid(part);
+  const b = bbox(part);
+  manifest[key] = {
+    lat: round6(c.geometry.coordinates[1]),
+    lon: round6(c.geometry.coordinates[0]),
+    spread: round6(Math.min(b[2] - b[0], b[3] - b[1]) * 0.1),
+  };
+}
+
+// --- hard assertions (the test re-checks these against the committed file) ---
+const expectedKeys = Object.values(idToKey);
+if (Object.keys(manifest).length !== expectedKeys.length) {
+  throw new Error(
+    `expected ${expectedKeys.length} centroid entries (one per region key), got ${Object.keys(manifest).length}`,
+  );
+}
+for (const k of expectedKeys) {
+  if (!(k in manifest)) throw new Error(`missing centroid for region key ${JSON.stringify(k)}`);
+}
+for (const [k, v] of Object.entries(manifest)) {
+  if (!Number.isFinite(v.lat) || !Number.isFinite(v.lon) || !Number.isFinite(v.spread)) {
+    throw new Error(`non-finite centroid for ${k}: ${JSON.stringify(v)}`);
+  }
+  if (v.spread < 0) throw new Error(`negative spread for ${k}: ${v.spread}`);
+}
+
+// --- write idempotently (stable order = insertion order = geo file order) ---
+writeFileSync(path.join(root, 'public', 'region-centroids.json'), JSON.stringify(manifest, null, 2) + '\n');
+
+// --- summary ------------------------------------------------------------------
+const spreads = Object.values(manifest).map((v) => v.spread);
+console.log(
+  `[build-region-centroids] wrote public/region-centroids.json — ${Object.keys(manifest).length} region keys` +
+    (skipped ? ` (${skipped} non-polygon fallbacks)` : '') +
+    `, spread min/max ${Math.min(...spreads)} / ${Math.max(...spreads)} deg`,
+);

scripts/build-region-keys.mjs

@@ -21,7 +21,7 @@
  *     SQLite and shown to the LLM. Within any name-slug group (e.g. the six
  *     regions all named "Western") the 4-char codes are made distinct by
  *     re-deriving with a deterministic salt on collision, which guarantees the
- *     full key is unique across all 1,796 regions.
+ *     full key is unique across all 1,800 regions.
  *
  * Output: `public/region-keys.json` — a `{ [stableFeatureId]: regionKey }`
  * object, e.g. `{ "FR-57": "brittany-xk2a" }`, in file (stable) order. The map
@@ -107,8 +107,8 @@ const geoFile = path.join(root, 'public', 'regions.geo.json');
 const geo = JSON.parse(readFileSync(geoFile, 'utf8'));
 const features = Array.isArray(geo?.features) ? geo.features : [];
 
-if (features.length !== 1796) {
-  throw new Error(`expected 1,796 regions, got ${features.length} — regions.geo.json changed; re-verify the region-key contract`);
+if (features.length !== 1800) {
+  throw new Error(`expected 1,800 regions, got ${features.length} — regions.geo.json changed; re-verify the region-key contract`);
 }
 
 // Group features by their (computed) name-slug, preserving file order, so the
@@ -154,5 +154,5 @@ writeFileSync(path.join(root, 'public', 'region-keys.json'), out);
 const western = Object.entries(manifest)
   .filter(([, k]) => k.startsWith('western-'))
   .sort((a, b) => a[0] < b[0] ? -1 : 1);
-console.log(`[build-region-keys] wrote public/region-keys.json — ${keys.length} unique region keys (1,796 expected)`);
+console.log(`[build-region-keys] wrote public/region-keys.json — ${keys.length} unique region keys (1,800 expected)`);
 console.log(`  western group: ${western.map(([id, k]) => `${id}=${k}`).join(', ')}`);

scripts/region-adjacency.test.ts

@@ -0,0 +1,115 @@
+/**
+ * scripts/region-adjacency.test.ts — validation for the committed
+ * `public/region-adjacency.json` (built by `scripts/build-region-adjacency.mjs`).
+ *
+ * The manifest maps each region key to the list of region keys it **borders**
+ * (shares an edge/point with). It is the data behind the model's `getNeighbours`
+ * tool (v0.21, #16 P2), so it is a load-bearing data artifact — this test pins
+ * its contract.
+ *
+ * Deliberately dependency-free: it reads the JSON with plain `fs`/`JSON.parse`
+ * and never imports `@turf`/geojson types (importing one pulls `@types/geojson`
+ * into the tsc program and breaks `WorldMap.tsx`; see the v0.17 changelog note).
+ * Mirrors the style of `scripts/region-keys.test.ts`.
+ */
+import { readFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, it } from 'vitest';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+
+function readJson(rel: string): Record<string, unknown> {
+  return JSON.parse(readFileSync(path.join(root, rel), 'utf8'));
+}
+
+describe('region-adjacency.json', () => {
+  const adjacency = readJson('public/region-adjacency.json') as Record<string, string[]>;
+  const manifest = readJson('public/region-keys.json') as Record<string, string>;
+  const keys = new Set(Object.values(manifest));
+
+  it('has exactly one entry per region key (same key set as region-keys.json)', () => {
+    const manifestKeys = new Set(Object.values(manifest));
+    const adjacencyKeys = new Set(Object.keys(adjacency));
+    expect(adjacencyKeys).toEqual(manifestKeys);
+    expect(Object.keys(adjacency)).toHaveLength(keys.size);
+    expect(adjacencyKeys.size).toBe(1800);
+  });
+
+  it('every neighbour is itself a valid region key (referential integrity)', () => {
+    for (const [key, neighbours] of Object.entries(adjacency)) {
+      for (const n of neighbours) {
+        expect(keys.has(n), `neighbour ${n} of ${key} is not a valid region key`).toBe(true);
+      }
+    }
+  });
+
+  it('no region lists itself as a neighbour', () => {
+    for (const [key, neighbours] of Object.entries(adjacency)) {
+      expect(neighbours.includes(key), `${key} lists itself`).toBe(false);
+    }
+  });
+
+  it('adjacency is symmetric (A ∈ B  ⟺  B ∈ A)', () => {
+    let checked = 0;
+    for (const [a, aList] of Object.entries(adjacency)) {
+      const aSet = new Set(aList);
+      for (const b of aList) {
+        const bList = adjacency[b];
+        expect(Array.isArray(bList), `${b} has no adjacency entry`).toBe(true);
+        // A lists B, so B must list A.
+        expect(bList!.includes(a), `${a} → ${b} but ${b} does not list ${a}`).toBe(true);
+        checked++;
+      }
+      // And the converse: every neighbour B of A must be a key (implied above) —
+      // also assert no *missing* reverse entry by checking the full set equality.
+      const bSet = new Set(aSet);
+      for (const b of aList) bSet.add(b);
+      // Symmetry means a's set equals the set of {b : a ∈ b}.
+      const reverse = Object.entries(adjacency)
+        .filter(([, list]) => list.includes(a))
+        .map(([k]) => k);
+      expect(new Set(reverse).size, `asymmetric degree for ${a}`).toBe(aList.length);
+      expect(new Set(aList).size).toBe(aSet.size); // no duplicate neighbours
+    }
+    expect(checked).toBeGreaterThan(0);
+  });
+
+  it('spot-checks known real bordering pairs', () => {
+    // Brazil ↔ Peru (Acre borders Loreto) — a real, unambiguous land border.
+    expect(adjacency['acre-ekzw']?.includes('loreto-ipkx')).toBe(true);
+    expect(adjacency['loreto-ipkx']?.includes('acre-ekzw')).toBe(true);
+    // France ↔ Germany (Moselle borders Baden-Württemberg) — another real border.
+    expect(adjacency['moselle-rygy']?.includes('baden-wurttemberg-oyje')).toBe(true);
+    expect(adjacency['baden-wurttemberg-oyje']?.includes('moselle-rygy')).toBe(true);
+  });
+
+  it("the #31 + #41 Arctic splits: New Earth isolated; Severnaya Zemlya, Pechora and Yamal adjacency", () => {
+    // v0.25 (#31) split RU-ARK into the mainland (arkhangel-sk-lhbk), the
+    // Franz Josef Land islets (new-earth-eikt) and the Severnaya Zemlya
+    // islets (severnaya-zemlya-awqp). New Earth sits ~100+ km from any land
+    // → a genuinely isolated island (empty list).
+    // v0.26 (#41) repartitioned the mainland: the 5 lat < 68 parts stay
+    // arkhangel-sk-lhbk, and the 28 lat ≥ 68 band parts became pechora-qwhs
+    // (the SW cell) and yamal-gosw (the NE cell). The Severnaya Zemlya
+    // islets' digitized rings touch the NE band part (now yamal-gosw), not
+    // the trimmed core, so SZ now borders Yamal (its former mainland contact
+    // moved to Yamal). The trimmed core keeps its real mainland neighbours
+    // but loses the SZ contact. Pechora (SW) borders the existing Nenets
+    // region to the south and Yamal to the north.
+    expect(adjacency['new-earth-eikt']).toEqual([]);
+    expect(adjacency['severnaya-zemlya-awqp']).toEqual(['yamal-gosw']);
+    expect(adjacency['pechora-qwhs']).toEqual(['nenets-qyga', 'yamal-gosw']);
+    expect(adjacency['yamal-gosw']).toEqual(['pechora-qwhs', 'severnaya-zemlya-awqp']);
+    // the trimmed core keeps its real neighbours (the band's SZ contact moved to Yamal)
+    expect(adjacency['arkhangel-sk-lhbk']).toEqual([
+      'karelia-ohem',
+      'kirov-gfvm',
+      'komi-eoeh',
+      'murmansk-etas',
+      'nenets-qyga',
+      'vologda-ynvr',
+    ]);
+  });
+});

scripts/region-centroids.test.ts

@@ -0,0 +1,158 @@
+/**
+ * scripts/region-centroids.test.ts — validation for the committed
+ * `public/region-centroids.json` (built by `scripts/build-region-centroids.mjs`).
+ *
+ * The manifest maps each region key to the anchor point a map marker (v0.27,
+ * #44) is placed at: the centroid of the region's largest-area part, plus a
+ * `spread` (≈ 0.1 × that part's smallest bbox dimension, in degrees) that the
+ * engine uses to scatter multiple markers of one region around the centroid.
+ * It is a load-bearing data artifact for the marker placement path — this test
+ * pins its contract.
+ *
+ * Deliberately dependency-free: it reads the JSON with plain `fs`/`JSON.parse`
+ * and computes bbox checks by iterating coordinates directly (no `@turf`/
+ * geojson types, which would pull `@types/geojson` into the tsc program and
+ * break `WorldMap.tsx` — see the v0.17 note). Mirrors the style of
+ * `scripts/region-adjacency.test.ts`; the determinism test re-runs the (turf
+ * `.mjs`) builder and compares bytes, matching that the builder is idempotent.
+ */
+import { readFileSync } from 'node:fs';
+import { execFileSync } from 'node:child_process';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { describe, expect, it } from 'vitest';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+
+function readJson(rel: string): Record<string, unknown> {
+  return JSON.parse(readFileSync(path.join(root, rel), 'utf8'));
+}
+
+interface CentroidEntry {
+  lat: number;
+  lon: number;
+  spread: number;
+}
+
+/** All [lon, lat] coordinate pairs of a Polygon / MultiPolygon geometry. */
+function allCoords(geometry: { type?: string; coordinates?: unknown }): Array<[number, number]> {
+  const c = geometry?.coordinates as
+    | Array<Array<[number, number]>>
+    | Array<Array<Array<[number, number]>>>
+    | undefined;
+  if (!c) return [];
+  if (geometry?.type === 'Polygon') {
+    const rings = c as Array<Array<[number, number]>>;
+    const out: Array<[number, number]> = [];
+    for (const ring of rings) for (const p of ring) out.push(p);
+    return out;
+  }
+  if (geometry?.type === 'MultiPolygon') {
+    const polys = c as Array<Array<Array<[number, number]>>>;
+    const out: Array<[number, number]> = [];
+    for (const poly of polys) for (const ring of poly) for (const p of ring) out.push(p);
+    return out;
+  }
+  return [];
+}
+
+/** The bounding box [minLon, minLat, maxLon, maxLat] of a geometry. */
+function bboxOf(geometry: { type?: string; coordinates?: unknown }): [number, number, number, number] {
+  let minLon = Infinity;
+  let minLat = Infinity;
+  let maxLon = -Infinity;
+  let maxLat = -Infinity;
+  for (const [x, y] of allCoords(geometry)) {
+    if (x < minLon) minLon = x;
+    if (y < minLat) minLat = y;
+    if (x > maxLon) maxLon = x;
+    if (y > maxLat) maxLat = y;
+  }
+  return [minLon, minLat, maxLon, maxLat];
+}
+
+describe('region-centroids.json', () => {
+  const centroids = readJson('public/region-centroids.json') as Record<string, CentroidEntry>;
+  const manifest = readJson('public/region-keys.json') as Record<string, string>;
+  const geo = readJson('public/regions.geo.json') as {
+    features?: Array<{ id?: string | number; geometry?: { type?: string; coordinates?: unknown } }>;
+  };
+  const keys = Object.values(manifest);
+
+  // featureId -> feature, then regionKey -> feature (via the key manifest).
+  const featureByKey = new Map<string, { geometry?: { type?: string; coordinates?: unknown } }>();
+  for (const f of geo.features ?? []) {
+    const key = manifest[String(f.id)];
+    if (key) featureByKey.set(key, f);
+  }
+
+  it('has exactly one entry per region key (same key set as region-keys.json)', () => {
+    expect(new Set(Object.keys(centroids))).toEqual(new Set(keys));
+    expect(Object.keys(centroids)).toHaveLength(1800);
+  });
+
+  it('every entry is a finite { lat, lon, spread } with a non-negative spread, in world bounds', () => {
+    for (const [k, v] of Object.entries(centroids)) {
+      expect(Number.isFinite(v.lat), `non-finite lat for ${k}`).toBe(true);
+      expect(Number.isFinite(v.lon), `non-finite lon for ${k}`).toBe(true);
+      expect(Number.isFinite(v.spread), `non-finite spread for ${k}`).toBe(true);
+      expect(v.spread >= 0, `negative spread for ${k}`).toBe(true);
+      expect(v.lat >= -90 && v.lat <= 90, `lat out of range for ${k}: ${v.lat}`).toBe(true);
+      expect(v.lon >= -180 && v.lon <= 180, `lon out of range for ${k}: ${v.lon}`).toBe(true);
+    }
+  });
+
+  it('each centroid lies inside its region feature bounding box', () => {
+    // The recorded point is the centroid of the LARGEST part, which is a subset
+    // of the whole feature, so it must fall inside the feature's overall bbox.
+    let checked = 0;
+    for (const [key, c] of Object.entries(centroids)) {
+      const feat = featureByKey.get(key);
+      if (!feat?.geometry) continue;
+      const [minLon, minLat, maxLon, maxLat] = bboxOf(feat.geometry);
+      const eps = 1e-4; // allow for the 6-dp rounding in the builder
+      expect(
+        c.lat >= minLat - eps && c.lat <= maxLat + eps,
+        `lat ${c.lat} outside bbox [${minLat}, ${maxLat}] for ${key}`,
+      ).toBe(true);
+      expect(
+        c.lon >= minLon - eps && c.lon <= maxLon + eps,
+        `lon ${c.lon} outside bbox [${minLon}, ${maxLon}] for ${key}`,
+      ).toBe(true);
+      checked++;
+    }
+    expect(checked).toBe(1800);
+  });
+
+  it('spot-checks a couple of well-known anchors land in the right place', () => {
+    // Region keys are sub-national (states/provinces), so we spot-check a few
+    // whose geography is unambiguous. A gross error in the centroid method
+    // (e.g. averaging across all parts of a large multi-part region, or a
+    // lon/lat swap) would land one of these far off.
+    const near = (k: string, lat: number, lon: number, tol: number) => {
+      const c = centroids[k];
+      expect(c, `missing centroid for ${k}`).toBeDefined();
+      expect(Math.abs(c!.lat - lat)).toBeLessThan(tol);
+      expect(Math.abs(c!.lon - lon)).toBeLessThan(tol);
+    };
+    near('ain-lqtt', 46.16, 4.8, 0.5); // FR-01 — eastern France
+    near('california-kikh', 36.87, -120.67, 0.7); // US-CA — central California
+    near('alberta-zopq', 52.09, -116.94, 1.5); // CA-AB — Alberta (large province)
+    near('acre-ekzw', -9.49, -71.11, 0.5); // BR-AC — western Brazil
+  });
+
+  it('is deterministic: re-running the builder rewrites a byte-identical file', () => {
+    const file = path.join(root, 'public', 'region-centroids.json');
+    const before = readFileSync(file, 'utf8');
+    // The builder is cwd-independent (it resolves the repo root from its own
+    // location) and idempotent: same input files + pure turf + fixed rounding
+    // + stable insertion order → identical bytes.
+    execFileSync(process.execPath, [path.join(root, 'scripts', 'build-region-centroids.mjs')], {
+      cwd: root,
+      stdio: 'pipe',
+    });
+    const after = readFileSync(file, 'utf8');
+    expect(after).toBe(before);
+  });
+});

scripts/region-keys.test.ts

@@ -33,13 +33,13 @@ describe('region-keys.json', () => {
   const keys = Object.values(manifest);
   const featureIds = (geo.features ?? []).map((f) => String(f.id));
 
-  it('has exactly 1,796 entries (one per region)', () => {
-    expect(Object.keys(manifest)).toHaveLength(1796);
+  it('has exactly 1,800 entries (one per region)', () => {
+    expect(Object.keys(manifest)).toHaveLength(1800);
   });
 
-  it('has 1,796 unique keys (no collisions)', () => {
+  it('has 1,800 unique keys (no collisions)', () => {
     expect(new Set(keys).size).toBe(keys.length);
-    expect(new Set(keys).size).toBe(1796);
+    expect(new Set(keys).size).toBe(1800);
   });
 
   it('keys each end in -[a-z]{4} and contain at least one hyphen', () => {
@@ -50,11 +50,26 @@ describe('region-keys.json', () => {
     }
   });
 
+  it("keeps RU-ARK's key stable across the #31 + #41 splits and mints the island and band keys", () => {
+    // v0.25 (#31) split RU-ARK into main + RU-ARK-NE + RU-ARK-SZ, and v0.26
+    // (#41) repartitioned the mainland into the core (RU-ARK) + RU-PEO +
+    // RU-YAM. The MAIN feature keeps its id (and therefore its key — FNV-1a
+    // of the id), which is what keeps existing Nation.territory / SQLite
+    // ownership valid; the new features get fresh keys derived the same way
+    // from their ids (no within-country name-collision salt needed — the
+    // slugs are unique).
+    expect(manifest['RU-ARK']).toBe('arkhangel-sk-lhbk'); // unchanged since v0.19
+    expect(manifest['RU-ARK-NE']).toBe('new-earth-eikt');
+    expect(manifest['RU-ARK-SZ']).toBe('severnaya-zemlya-awqp');
+    expect(manifest['RU-PEO']).toBe('pechora-qwhs');
+    expect(manifest['RU-YAM']).toBe('yamal-gosw');
+  });
+
   it('is a stable join: its keys are exactly the regions.geo.json feature ids', () => {
     // The manifest is looked up by feature id, so its key set must line up
     // 1:1 with the geo file (catches drift if the geo is regenerated without
     // rebuilding the keys).
-    expect(featureIds).toHaveLength(1796);
+    expect(featureIds).toHaveLength(1800);
     const manifestIds = Object.keys(manifest);
     expect(new Set(manifestIds)).toEqual(new Set(featureIds));
   });

scripts/regions.test.ts

@@ -530,16 +530,22 @@ describe('regions.geo.json', () => {
     );
   });
 
-  it('is at the v0.17 fixed point: 1,796 regions, 11,794 parts, 11,795 rings, 164,801 vertices, 1 hole (KZ-KZY)', () => {
+  it('is at the v0.26 fixed point: 1,800 regions, 11,794 parts, 11,795 rings, 164,801 vertices, 1 hole (KZ-KZY)', () => {
     // v0.17 (scripts/fill-gaps.mjs) APPENDED cleaned gap pieces to the v0.16
     // fixed point: it never moves an existing border, merges a part, or
     // removes a ring — it only adds new parts (+6,768: 5,026 → 11,794) and
-    // keeps the single KZ-KZY hole. The region count (1,796), the
-    // per-feature ids/names/parents and their order are unchanged; only the
-    // part/ring/vertex totals and the hole's part structure moved. Pinning
-    // the signature guards against a non-idempotent or destructive re-run.
-    // The fill is byte-deterministic per input and idempotent (a second run
-    // on the filled file changes nothing).
+    // keeps the single KZ-KZY hole. The v0.25 Arkhangel'sk split (#31,
+    // scripts/split-arkhangel.mjs) then repartitioned the 78 RU-ARK parts
+    // across three features (RU-ARK + RU-ARK-NE + RU-ARK-SZ), and the v0.26
+    // band split (#41, scripts/split-arkhangel-band.mjs) repartitioned the
+    // 33-part mainland again into RU-ARK + RU-PEO + RU-YAM. Both are pure
+    // re-groupings: no part/ring/vertex moves, so only the region count
+    // changed (1,796 → 1,798 → 1,800); the part/ring/vertex totals, the
+    // per-feature ids/names/parents, and the feature order (the new features
+    // sit immediately after RU-ARK-SZ) are as pinned below. Pinning the
+    // signature guards against a non-idempotent or destructive re-run; both
+    // stages are byte-deterministic per input and idempotent (a second run
+    // changes nothing).
     const polysOf = (g: Geometry) => (g.type === 'Polygon' ? [g.coordinates] : g.coordinates);
     let verts = 0,
       rings = 0,
@@ -556,15 +562,67 @@ describe('regions.geo.json', () => {
         for (const ring of poly) verts += ring.length;
       }
     }
-    expect(regions.features.length, 'region count').toBe(1796); // unchanged by the fill
-    expect(parts, 'parts').toBe(11_794); // v0.16: 5,026 → +6,768 appended gap pieces
+    expect(regions.features.length, 'region count').toBe(1800); // 1,796 + the #31 islands (+2) + the #41 band regions (+2)
+    expect(parts, 'parts').toBe(11_794); // v0.16: 5,026 → +6,768 appended gap pieces; unchanged by the #31/#41 re-partitions
     expect(rings, 'rings').toBe(11_795); // every appended part is a single-ring polygon (+1 hole = KZ-KZY, pre-existing)
     expect(holes, 'holes').toBe(1); // the single KZ-KZY hole, unchanged
     expect(holeIds, 'the one remaining hole is KZ-KZY').toEqual(['KZ-KZY']);
-    expect(verts, 'total vertices (incl. ring closure)').toBe(164_801); // v0.16: 111,175
+    expect(verts, 'total vertices (incl. ring closure)').toBe(164_801); // v0.16: 111,175; unchanged by the #31/#41 re-partitions
     console.log(
-      `\n  v0.17 gap fill: ${regions.features.length} regions, ${parts} parts, ${rings} rings, ` +
-        `${holes} hole (KZ-KZY), ${verts} vertices — v0.16 topology preserved, 6,768 gap pieces appended`,
+      `\n  v0.26 fixed point: ${regions.features.length} regions (1,796 + the #31 islands + the #41 band), ` +
+        `${parts} parts, ${rings} rings, ${holes} hole (KZ-KZY), ${verts} vertices — v0.17 topology preserved`,
+    );
+  });
+
+  it('has the five Arkhangel\'sk-family features: #31 islands + #41 band (RU-ARK, New Earth, Severnaya Zemlya, Pechora, Yamal)', () => {
+    // v0.25 (#31): the ~411,500 km² RU-ARK mega-region (a 78-part MultiPolygon
+    // mixing mainland and far-north islands) was repartitioned by part
+    // centroid into the mainland (RU-ARK, keeps its id/name/key), the Franz
+    // Josef Land islets (RU-ARK-NE "New Earth", centroid lat ≥ 79.5) and the
+    // Severnaya Zemlya islets (RU-ARK-SZ, centroid 76–79.5° N, lon ≥ 55°E).
+    // v0.26 (#41): the 33-part mainland (post-#31) was repartitioned again —
+    // the 5 lat < 68 parts stay RU-ARK (id/name/key unchanged), and the 28
+    // lat ≥ 68 "Arctic-coast band" parts split into RU-PEO "Pechora" (the SW
+    // Voronoi cell, 13 parts) and RU-YAM "Yamal" (the NE Voronoi cell, 15
+    // parts). Pure re-grouping: all five keep parent RUS and all 78 original
+    // parts of the pre-#31 feature are accounted for, verbatim.
+    const byId = new Map(regions.features.map((f) => [f.id, f]));
+    const ark = byId.get('RU-ARK');
+    const ne = byId.get('RU-ARK-NE');
+    const sz = byId.get('RU-ARK-SZ');
+    const peo = byId.get('RU-PEO');
+    const yam = byId.get('RU-YAM');
+    for (const f of [ark, ne, sz, peo, yam]) {
+      expect(f, `${f?.id ?? '?'} exists`).toBeDefined();
+      expect(f!.properties.parent, `${f!.id} parent`).toBe('RUS');
+      expect(f!.geometry.type, `${f!.id} geometry`).toBe('MultiPolygon');
+    }
+    expect(ark!.properties.name, 'RU-ARK keeps its name').toBe("Arkhangel'sk");
+    expect(ne!.properties.name, 'RU-ARK-NE name').toBe('New Earth');
+    expect(sz!.properties.name, 'RU-ARK-SZ name').toBe('Severnaya Zemlya');
+    expect(peo!.properties.name, 'RU-PEO name').toBe('Pechora');
+    expect(yam!.properties.name, 'RU-YAM name').toBe('Yamal');
+    // the 78 parts of the pre-split feature are all accounted for, verbatim
+    const countParts = (f: (typeof regions.features)[number]) =>
+      f.geometry.type === 'MultiPolygon' ? f.geometry.coordinates.length : 1;
+    expect(
+      countParts(ark!) + countParts(ne!) + countParts(sz!) + countParts(peo!) + countParts(yam!),
+      'total parts across the five features',
+    ).toBe(78);
+    // the #41 split: the mainland core keeps its 5 lat < 68 parts; the band's
+    // 28 parts split 13 (Pechora) / 15 (Yamal)
+    expect(countParts(ark!), 'RU-ARK core part count').toBe(5);
+    expect(countParts(peo!), 'RU-PEO part count').toBe(13);
+    expect(countParts(yam!), 'RU-YAM part count').toBe(15);
+    // stable file order: RU-ARK, RU-ARK-NE, RU-ARK-SZ, RU-PEO, RU-YAM
+    const idx = regions.features.findIndex((f) => f.id === 'RU-ARK');
+    expect(regions.features[idx + 1]?.id).toBe('RU-ARK-NE');
+    expect(regions.features[idx + 2]?.id).toBe('RU-ARK-SZ');
+    expect(regions.features[idx + 3]?.id).toBe('RU-PEO');
+    expect(regions.features[idx + 4]?.id).toBe('RU-YAM');
+    console.log(
+      `\n  #31 + #41: RU-ARK ${countParts(ark!)} parts (core), RU-ARK-NE ${countParts(ne!)} (New Earth), ` +
+        `RU-ARK-SZ ${countParts(sz!)} (Severnaya Zemlya), RU-PEO ${countParts(peo!)} (Pechora), RU-YAM ${countParts(yam!)} (Yamal)`,
     );
   });
 });

scripts/split-arkhangel-band.mjs

@@ -0,0 +1,247 @@
+#!/usr/bin/env node
+/**
+ * scripts/split-arkhangel-band.mjs — split the RU-ARK Arctic-coast band into
+ * two new regions, RU-PEO ("Pechora", the SW group) and RU-YAM ("Yamal", the
+ * NE group) (issue #41, a follow-up to #31).
+ *
+ * The #31 split (`scripts/split-arkhangel.mjs`) left `RU-ARK` as a 33-part
+ * MultiPolygon (~393,256 km²). Measured on that feature (centroid latitude /
+ * planar area), the parts divide cleanly by centroid latitude:
+ *
+ *   lat < 68            4 parts  ~305,000 km²  (Arkhangel'sk proper + 3 slivers)
+ *   66 ≤ lat < 68       1 part   ~47 km²
+ *   lat ≥ 68            28 parts ~88,000 km²   (the "Arctic-coast band")
+ *
+ * The band is really *other* Arctic oblasts (Nenets / Pechora / Yamal / Taimyr
+ * side) mis-lumped into Arkhangel'sk during the v0.14 coarsening. This stage
+ * re-coarsens it: the 28 band parts are split into two new regions by a
+ * Voronoi of the two band parts with the largest planar area (the SW anchor
+ * vs the NE anchor), while the 5 lat < 68 parts stay in `RU-ARK`.
+ *
+ *   RU-ARK   (keeps its id and name)  — the 5 lat < 68 parts (original order)
+ *                                          → still the `arkhangel-sk-lhbk` key
+ *   RU-PEO   "Pechora"                — the band's SW Voronoi cell (13 parts)
+ *   RU-YAM   "Yamal"                  — the band's NE Voronoi cell (15 parts)
+ *
+ * Deterministic, turf-free threshold spec (all data-derived — no magic
+ * coordinates; the same planar model the tests/adjacency build use):
+ *   1. centroid of a part = the mean of its outer-ring vertices (verified to
+ *      give the same band assignment as turf's area-weighted centroid, 0 flips).
+ *   2. band = the parts whose centroid lat ≥ 68 (asserted to be exactly 28).
+ *   3. anchors = the 2 band parts with the largest planar area (≈ 47,223 and
+ *      ≈ 32,907 km², indices 2 and 1 in the 33-part feature); anchorW = the
+ *      anchor with the smaller centroid longitude.
+ *   4. each non-anchor band part → the nearer anchor by km-weighted centroid
+ *      distance, `dist(a,b) = hypot(Δlon·111.32·cos(midLat), Δlat·110.574)`;
+ *      a tie → west (anchorW). Each anchor → its own group. This yields
+ *      PEO = {1,4,5,9,11,12,13,14,16,17,18,20,22} and
+ *      YAM = {2,6,15,19,21,23,24,25,26,27,28,29,30,31,32} (0-based indices).
+ *
+ * PURE REPARTITION — no geometry is created, moved, or altered: each part is
+ * moved verbatim (same coordinates, same ring order) from the one feature to
+ * the others. The union of the three output geometries is byte-identical to
+ * the input feature's parts, so no border moves and no new overlap is
+ * possible (the same guarantee as #31). `RU-ARK` keeps its stable feature id,
+ * so its region key (`arkhangel-sk-lhbk`, FNV-1a of the id) and every existing
+ * `Nation.territory` / SQLite ownership referencing it stays valid; the two
+ * new ids (`RU-PEO`, `RU-YAM`) get their own keys derived by the same FNV-1a
+ * rule in `scripts/build-region-keys.mjs` (`pechora-qwhs`, `yamal-gosw` —
+ * run it after this stage).
+ *
+ * The new features are inserted immediately after `RU-ARK-SZ` (stable file
+ * order, deterministic bytes: `RU-ARK, RU-ARK-NE, RU-ARK-SZ, RU-PEO, RU-YAM,
+ * …`). Each new feature's `properties` copies `RU-ARK`'s (only `name` and
+ * `parent` exist in this dataset) with `name` overridden; `parent` stays RUS.
+ * Each feature's geometry is a MultiPolygon of its assigned parts (in
+ * original order), or a single Polygon if it ended up with one part (it won't
+ * here, but the builder handles it).
+ *
+ * Pipeline position: AFTER `split-arkhangel` and BEFORE `build-region-keys`
+ * (the manifests must be rebuilt after any geo change):
+ *
+ *   generate → coarsen → cleanup → smooth → fill-gaps → split-arkhangel
+ *   → **split-arkhangel-band** → build-region-keys → build-region-adjacency
+ *
+ * Idempotent: when RU-PEO and RU-YAM already exist the file is left untouched
+ * (no write at all), so a full re-run of the pipeline reproduces byte-identical
+ * output.
+ *
+ * Usage:  node scripts/split-arkhangel-band.mjs [inFile [outFile]]
+ *          (or `npm run split:regions:band`)
+ *   inFile  default: public/regions.geo.json
+ *   outFile default: inFile (edit in place)
+ *
+ * Deliberately turf-free: no `@turf/*` import (turf is only ever imported by
+ * the geo-generator `.mjs` stages, never by this re-partition or by any `.ts`).
+ */
+import { readFileSync, writeFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+const inFile = process.argv[2] ?? path.join(root, 'public', 'regions.geo.json');
+const outFile = process.argv[3] ?? inFile;
+
+// A part whose centroid lat is ≥ this is part of the Arctic-coast band; the
+// lat < 68 core stays in RU-ARK (issue #41).
+const BAND_MIN_LAT = 68;
+
+// The post-#31 mainland feature is a 33-part MultiPolygon; any other shape
+// means the file is not the state this stage expects → fail loud.
+const EXPECTED_PARTS = 33;
+// The Arctic-coast band is exactly 28 of those parts (lat ≥ 68).
+const EXPECTED_BAND = 28;
+
+// Planar km model (matches the test's area model and the adjacency build):
+// x = lon · 111.32 · cos(midLat), y = lat · 110.574.
+const KM_LON = 111.32;
+const KM_LAT = 110.574;
+const rad = (deg) => (deg * Math.PI) / 180;
+
+/**
+ * Mean of a part's outer-ring vertices — a turf-free centroid. Verified to give
+ * the same band assignment as turf's area-weighted centroid (0 flips).
+ */
+function centroidOf(part) {
+  const ring = part[0];
+  let lon = 0;
+  let lat = 0;
+  for (const [lo, la] of ring) {
+    lon += lo;
+    lat += la;
+  }
+  return [lon / ring.length, lat / ring.length];
+}
+
+/** Planar area of a part (km²), shoelace over its outer ring at its mean latitude. */
+function areaKm2(part) {
+  const ring = part[0];
+  let lat = 0;
+  for (const [, la] of ring) lat += la;
+  const midLat = lat / ring.length;
+  const kx = KM_LON * Math.cos(rad(midLat));
+  let a = 0;
+  for (let i = 0; i < ring.length; i++) {
+    const [lon1, lat1] = ring[i];
+    const [lon2, lat2] = ring[(i + 1) % ring.length];
+    a += lon1 * kx * (lat2 * KM_LAT) - lon2 * kx * (lat1 * KM_LAT);
+  }
+  return Math.abs(a / 2);
+}
+
+/** Planar km distance between two centroids (midpoint-latitude weighted). */
+function kmDist(a, b) {
+  const dLon = b[0] - a[0];
+  const dLat = b[1] - a[1];
+  const midLat = (a[1] + b[1]) / 2;
+  return Math.hypot(dLon * KM_LON * Math.cos(rad(midLat)), dLat * KM_LAT);
+}
+
+// --- load --------------------------------------------------------------------
+const geo = JSON.parse(readFileSync(inFile, 'utf8'));
+if (geo?.type !== 'FeatureCollection' || !Array.isArray(geo.features)) {
+  throw new Error(`${inFile} is not a FeatureCollection`);
+}
+const features = geo.features;
+
+// --- idempotency: already split? ----------------------------------------------
+const ids = new Set(features.map((f) => String(f.id ?? '')));
+if (ids.has('RU-PEO') && ids.has('RU-YAM')) {
+  console.log(
+    `[split-arkhangel-band] RU-PEO and RU-YAM already present — no-op (idempotent), ${inFile} left untouched`,
+  );
+  process.exit(0);
+}
+
+// --- load + validate RU-ARK ---------------------------------------------------
+const idx = features.findIndex((f) => f.id === 'RU-ARK');
+if (idx < 0) throw new Error('RU-ARK not found in ' + inFile);
+const ark = features[idx];
+if (ark.geometry?.type !== 'MultiPolygon') {
+  throw new Error(
+    `RU-ARK geometry is ${ark.geometry?.type}, expected MultiPolygon (the 33-part post-#31 mainland)`,
+  );
+}
+const parts = ark.geometry.coordinates;
+if (parts.length !== EXPECTED_PARTS) {
+  throw new Error(`RU-ARK has ${parts.length} parts, expected ${EXPECTED_PARTS} (the post-#31 mainland)`);
+}
+
+// --- band selection (centroid lat ≥ 68) and the lat < 68 core -----------------
+const partsByIndex = parts.map((p, i) => ({ i, c: centroidOf(p) }));
+const band = partsByIndex.filter((o) => o.c[1] >= BAND_MIN_LAT);
+if (band.length !== EXPECTED_BAND) {
+  throw new Error(`expected exactly ${EXPECTED_BAND} Arctic-coast band parts (lat ≥ ${BAND_MIN_LAT}), found ${band.length}`);
+}
+const core = partsByIndex.filter((o) => o.c[1] < BAND_MIN_LAT);
+
+// --- anchors: the two band parts with the largest planar area -----------------
+// (≈ 47,223 and ≈ 32,907 km², indices 2 and 1 in the 33-part feature).
+const byArea = [...band].sort((a, b) => areaKm2(parts[b.i]) - areaKm2(parts[a.i]));
+const big = byArea[0];
+const small = byArea[1];
+const anchorW = big.c[0] <= small.c[0] ? big : small; // the west (SW) anchor
+const anchorE = big.c[0] <= small.c[0] ? small : big; // the east (NE) anchor
+
+// --- assignment (Voronoi by km-weighted centroid distance; tie → west) --------
+const peo = new Set([anchorW.i]);
+const yam = new Set([anchorE.i]);
+for (const o of band) {
+  if (o.i === anchorW.i || o.i === anchorE.i) continue;
+  const dW = kmDist(o.c, anchorW.c);
+  const dE = kmDist(o.c, anchorE.c);
+  (dW <= dE ? peo : yam).add(o.i); // a tie goes to the west (anchorW) group
+}
+
+// --- rebuild geometries (parts verbatim, original order; MultiPolygon/Polygon) --
+const geom = (ps) =>
+  ps.length > 1 ? { type: 'MultiPolygon', coordinates: ps } : { type: 'Polygon', coordinates: ps[0] };
+
+const coreParts = [...core].sort((a, b) => a.i - b.i).map((o) => parts[o.i]);
+const peoParts = [...peo].sort((a, b) => a - b).map((i) => parts[i]);
+const yamParts = [...yam].sort((a, b) => a - b).map((i) => parts[i]);
+
+ark.geometry = geom(coreParts);
+
+const mkFeature = (id, name, ps) => ({
+  type: 'Feature',
+  id,
+  // copy every property RU-ARK has (currently just { name, parent }), overriding name
+  properties: { ...ark.properties, name },
+  geometry: geom(ps),
+});
+const peoF = mkFeature('RU-PEO', 'Pechora', peoParts);
+const yamF = mkFeature('RU-YAM', 'Yamal', yamParts);
+
+// --- report -------------------------------------------------------------------
+const km2 = (ps) => ps.reduce((s, p) => s + areaKm2(p), 0);
+console.log(`[split-arkhangel-band] input: ${inFile}`);
+console.log(
+  `  RU-ARK  (core, lat < 68)   ${coreParts.length} parts (of ${parts.length}), ≈ ${Math.round(km2(coreParts)).toLocaleString('en-US')} km²`,
+);
+console.log(
+  `  RU-PEO  (Pechora, SW)      ${peoParts.length} parts, ≈ ${Math.round(km2(peoParts)).toLocaleString('en-US')} km²  [${[...peo].sort((a, b) => a - b).join(',')}]`,
+);
+console.log(
+  `  RU-YAM  (Yamal, NE)        ${yamParts.length} parts, ≈ ${Math.round(km2(yamParts)).toLocaleString('en-US')} km²  [${[...yam].sort((a, b) => a - b).join(',')}]`,
+);
+if (peoParts.length === 0 || yamParts.length === 0) {
+  throw new Error(
+    `threshold mis-split: Pechora=${peoParts.length} parts, Yamal=${yamParts.length} parts — check the band before shipping`,
+  );
+}
+
+// --- insert at a stable position (immediately after RU-ARK-SZ) and write -------
+// RU-ARK-SZ must exist (the #31 split ran first); if it doesn't, this stage is
+// being run out of order → fail loud.
+const szIdx = features.findIndex((f) => f.id === 'RU-ARK-SZ');
+if (szIdx < 0) {
+  throw new Error('RU-ARK-SZ not found — the #31 split (scripts/split-arkhangel.mjs) must run before this stage');
+}
+features.splice(szIdx + 1, 0, peoF, yamF);
+writeFileSync(outFile, JSON.stringify(geo));
+console.log(
+  `[split-arkhangel-band] wrote ${outFile} — features ${features.length - 2} → ${features.length}` +
+    ` (order …, RU-ARK, RU-ARK-NE, RU-ARK-SZ, RU-PEO, RU-YAM, …)`,
+);

scripts/split-arkhangel.mjs

@@ -0,0 +1,180 @@
+#!/usr/bin/env node
+/**
+ * scripts/split-arkhangel.mjs — split the RU-ARK ("Arkhangel'sk") mega-region
+ * into main + two detached island archipelagos (issue #31).
+ *
+ * `RU-ARK` is a 78-part MultiPolygon of ~411,500 km²: the Arkhangel'sk
+ * mainland plus Arctic-coast mainland parts, tiny islets, AND two far-north
+ * island groups that belong nowhere near the mainland — the Franz Josef Land
+ * islets (New Earth, centroid lat ≥ 79.5) and the Severnaya Zemlya islets
+ * (centroid lat 76–79.5, lon ≥ 55). This stage repartitions the existing
+ * polygon parts between three features so each island group is its own
+ * addressable sub-region:
+ *
+ *   RU-ARK     (keeps its id and name)  — every part whose centroid has
+ *                                         lat < 76 (the mainland, Arctic-coast
+ *                                         mainland parts, islets, one south dot)
+ *   RU-ARK-NE  "New Earth"              — every part whose centroid has
+ *                                         lat ≥ 79.5 (the 42 Franz Josef Land
+ *                                         islets, ~15,700 km²)
+ *   RU-ARK-SZ  "Severnaya Zemlya"       — every part whose centroid has
+ *                                         76 ≤ lat < 79.5 AND lon ≥ 55 (the 3
+ *                                         Severnaya Zemlya islets, ~1,200 km²)
+ *
+ * (Parts in the 76–79.5° band with lon < 55 would stay in RU-ARK; none exist
+ * in the current dataset — the split is verified clean before it is written.)
+ *
+ * PURE REPARTITION — no geometry is created, moved, or altered: each part is
+ * moved verbatim (same coordinates, same ring order) from the one feature to
+ * the other. The union of the three output geometries is byte-identical to
+ * the input feature's parts, so no border moves and no new overlap is
+ * possible. RU-ARK keeps its stable feature id, so its region key
+ * (`arkhangel-sk-lhbk`, FNV-1a of the id) and every existing
+ * `Nation.territory` / SQLite ownership referencing it stays valid; the two
+ * new ids (`RU-ARK-NE`, `RU-ARK-SZ`) get their own keys derived by the same
+ * FNV-1a rule in `scripts/build-region-keys.mjs` (run it after this stage).
+ *
+ * The new features are inserted immediately after RU-ARK (stable file order,
+ * deterministic bytes). Each new feature's `properties` copies RU-ARK's
+ * (only `name` and `parent` exist in this dataset) with `name` overridden;
+ * `parent` stays RUS. Each feature's geometry is a MultiPolygon of its
+ * assigned parts, or a single Polygon if it ends up with one part.
+ *
+ * Pipeline position: between `fill-gaps` and `build-region-keys` (the
+ * manifests must be rebuilt after any geo change):
+ *
+ *   generate → coarsen → cleanup → smooth → fill-gaps → **split-arkhangel**
+ *   → build-region-keys → build-region-adjacency
+ *
+ * Idempotent: when RU-ARK-NE and RU-ARK-SZ already exist the file is left
+ * untouched (no write at all), so a full re-run of the pipeline reproduces
+ * byte-identical output.
+ *
+ * Usage:  node scripts/split-arkhangel.mjs [inFile [outFile]]
+ *          (or `npm run split:regions`)
+ *   inFile  default: public/regions.geo.json
+ *   outFile default: inFile (edit in place)
+ *
+ * `@turf/centroid` + `@turf/helpers` are used only to classify each part by
+ * its centroid — the same measurement the split thresholds are defined in.
+ * (Turf is allowed in .mjs scripts only; never imported by any .ts file.)
+ */
+import { readFileSync, writeFileSync } from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import centroid from '@turf/centroid';
+import area from '@turf/area';
+import { polygon } from '@turf/helpers';
+
+const here = path.dirname(fileURLToPath(import.meta.url));
+const root = path.resolve(here, '..');
+const inFile = process.argv[2] ?? path.join(root, 'public', 'regions.geo.json');
+const outFile = process.argv[3] ?? inFile;
+
+// The split thresholds (degrees), per issue #31.
+const NEW_EARTH_MIN_LAT = 79.5; // centroid lat ≥ this → New Earth (Franz Josef Land)
+const SZ_BAND_MIN_LAT = 76; // centroid lat ≥ this (and < NEW_EARTH_MIN_LAT)…
+const SZ_MIN_LON = 55; // …and centroid lon ≥ this → Severnaya Zemlya
+// (anything else — including the 76–79.5° band west of 55°E, of which the
+// current dataset has none — stays in the main Arkhangel'sk feature)
+
+/** A GeoJSON polygon part as a turf Feature (for centroid/area only). */
+const partFeature = (part) => polygon(part);
+
+/**
+ * A part's centroid [lon, lat]. Strict by design: a centroid that cannot be
+ * computed is a data error, not something to silently route to the mainland.
+ */
+function centroidOf(part) {
+  try {
+    return centroid(partFeature(part)).geometry.coordinates;
+  } catch (err) {
+    throw new Error(`cannot compute centroid for a RU-ARK part: ${err.message}`);
+  }
+}
+
+/** Classify a centroid [lon, lat] into one of the three output buckets. */
+function bucketOf([lon, lat]) {
+  if (lat >= NEW_EARTH_MIN_LAT) return 'ne';
+  if (lat >= SZ_BAND_MIN_LAT && lat < NEW_EARTH_MIN_LAT && lon >= SZ_MIN_LON) return 'sz';
+  return 'main';
+}
+
+// --- load --------------------------------------------------------------------
+const geo = JSON.parse(readFileSync(inFile, 'utf8'));
+if (geo?.type !== 'FeatureCollection' || !Array.isArray(geo.features)) {
+  throw new Error(`${inFile} is not a FeatureCollection`);
+}
+const features = geo.features;
+
+// --- idempotency: already split? ----------------------------------------------
+const ids = new Set(features.map((f) => String(f.id ?? '')));
+if (ids.has('RU-ARK-NE') && ids.has('RU-ARK-SZ')) {
+  console.log(
+    `[split-arkhangel] RU-ARK-NE and RU-ARK-SZ already present — no-op (idempotent), ${inFile} left untouched`,
+  );
+  process.exit(0);
+}
+
+const idx = features.findIndex((f) => f.id === 'RU-ARK');
+if (idx < 0) {
+  throw new Error('RU-ARK not found in ' + inFile);
+}
+const ark = features[idx];
+if (ark.geometry?.type !== 'MultiPolygon') {
+  throw new Error(
+    `RU-ARK geometry is ${ark.geometry?.type}, expected MultiPolygon (the split expects the pre-#31 mega-region)`,
+  );
+}
+const parts = ark.geometry.coordinates;
+
+// --- partition (stable: original part order is kept inside each bucket) -------
+const buckets = { main: [], ne: [], sz: [] };
+let bandWest = 0; // 76–79.5°-band parts west of 55°E (stay in main; 0 in the current data)
+for (const part of parts) {
+  const [lon, lat] = centroidOf(part);
+  if (lat >= SZ_BAND_MIN_LAT && lat < NEW_EARTH_MIN_LAT && lon < SZ_MIN_LON) bandWest += 1;
+  buckets[bucketOf([lon, lat])].push(part);
+}
+
+// --- rebuild geometries (parts verbatim; MultiPolygon, or Polygon if 1 part) --
+const geom = (ps) =>
+  ps.length > 1
+    ? { type: 'MultiPolygon', coordinates: ps }
+    : { type: 'Polygon', coordinates: ps[0] };
+
+ark.geometry = geom(buckets.main);
+
+const mkFeature = (id, name, ps) => ({
+  type: 'Feature',
+  id,
+  // copy every property RU-ARK has (currently just { name, parent }), overriding name
+  properties: { ...ark.properties, name },
+  geometry: geom(ps),
+});
+const ne = mkFeature('RU-ARK-NE', 'New Earth', buckets.ne);
+const sz = mkFeature('RU-ARK-SZ', 'Severnaya Zemlya', buckets.sz);
+
+// --- report -------------------------------------------------------------------
+const km2 = (ps) => ps.reduce((s, p) => s + area(partFeature(p)) * 1e-6, 0);
+console.log(`[split-arkhangel] input: ${inFile}`);
+console.log(
+  `  RU-ARK    (main)  ${buckets.main.length} parts (of ${parts.length}), ≈ ${Math.round(km2(buckets.main)).toLocaleString('en-US')} km²` +
+    (bandWest ? ` — incl. ${bandWest} part(s) in the 76–79.5° band west of 55°E (kept in main)` : ''),
+);
+console.log(
+  `  RU-ARK-NE (New Earth)         ${buckets.ne.length} parts, ≈ ${Math.round(km2(buckets.ne)).toLocaleString('en-US')} km²`,
+);
+console.log(
+  `  RU-ARK-SZ (Severnaya Zemlya)  ${buckets.sz.length} parts, ≈ ${Math.round(km2(buckets.sz)).toLocaleString('en-US')} km²`,
+);
+if (buckets.ne.length === 0 || buckets.sz.length === 0) {
+  throw new Error(
+    `threshold mis-split: New Earth=${buckets.ne.length} parts, Severnaya Zemlya=${buckets.sz.length} parts — check the centroids before shipping`,
+  );
+}
+
+// --- insert at a stable position (immediately after RU-ARK) and write ---------
+features.splice(idx + 1, 0, ne, sz);
+writeFileSync(outFile, JSON.stringify(geo));
+console.log(`[split-arkhangel] wrote ${outFile} — features ${features.length - 2} → ${features.length}`);

server/db.test.ts

@@ -23,6 +23,9 @@ function makeState(id: string): GameState {
     events: [],
     pending: [],
     version: 1,
+    unowned: [],
+    pendingNationOps: [],
+    markers: [],
   };
 }
 
@@ -73,6 +76,39 @@ describe('openDb', () => {
     db.close();
   });
 
+  it('(v0.22 #16 P3) a legacy row saved before the unowned field existed loads with it defaulted to []', () => {
+    const db = openDb(':memory:');
+    const legacy = makeState('legacy');
+    delete (legacy as { unowned?: string[] }).unowned; // a pre-v0.22 save (field absent)
+    db.save(legacy);
+    const loaded = db.load('legacy');
+    expect(loaded).not.toBeNull();
+    expect(loaded!.unowned).toEqual([]);
+    db.close();
+  });
+
+  it('(v0.23 #16 P4a) a legacy row saved before the pendingNationOps field existed loads with it defaulted to []', () => {
+    const db = openDb(':memory:');
+    const legacy = makeState('legacy');
+    delete (legacy as { pendingNationOps?: unknown[] }).pendingNationOps; // a pre-v0.23 save (field absent)
+    db.save(legacy);
+    const loaded = db.load('legacy');
+    expect(loaded).not.toBeNull();
+    expect(loaded!.pendingNationOps).toEqual([]);
+    db.close();
+  });
+
+  it('(v0.27 #44) a legacy row saved before the markers field existed loads with it defaulted to []', () => {
+    const db = openDb(':memory:');
+    const legacy = makeState('legacy');
+    delete (legacy as { markers?: unknown[] }).markers; // a pre-v0.27 save (field absent)
+    db.save(legacy);
+    const loaded = db.load('legacy');
+    expect(loaded).not.toBeNull();
+    expect(loaded!.markers).toEqual([]);
+    db.close();
+  });
+
   it('delete removes a game by id and reports absence otherwise', () => {
     const db = openDb(':memory:');
     db.save(makeState('a'));

server/db.ts

@@ -39,7 +39,16 @@ export function openDb(filePath: string): Db {
       const row = byId.get(id) as { data: string } | undefined;
       if (!row) return null;
       try {
-        return JSON.parse(row.data) as GameState;
+        const state = JSON.parse(row.data) as GameState;
+        // (v0.22, #16 P3) Rows saved before `GameState.unowned` existed load
+        // with it defaulted: a legacy game has no no-man's-land regions.
+        if (state.unowned === undefined) state.unowned = [];
+        // (v0.23, #16 P4a) Same for pending nation-op proposals: a legacy game
+        // has none awaiting confirm/reject.
+        if (state.pendingNationOps === undefined) state.pendingNationOps = [];
+        // (v0.27, #44) Same for map markers: a legacy game has none placed.
+        if (state.markers === undefined) state.markers = [];
+        return state;
       } catch {
         return null;
       }

server/engine.ts

@@ -7,6 +7,9 @@ import type {
   EventOutcome,
   EventType,
   GameState,
+  MapMarker,
+  Nation,
+  NationStats,
   Preset,
   RelationStatus,
   RoundItem,
@@ -16,13 +19,27 @@ import { EVENT_TYPES, RELATION_STATUSES } from '../shared/types';
 import {
   addDays,
   clampStat,
+  fnv1a32,
   isDateLike,
+  isMarkerType,
   makeEvent,
+  markerId,
+  MAX_MARKERS,
   nationForPrompt,
+  type MarkerInfo,
+  type MarkerSpec,
+  type NationOp,
   type TurnEventSpec,
   type TurnResult,
 } from '../shared/protocol';
-import { DEFAULT_MAX_TOKENS, type LlmClient } from './llm';
+import {
+  DEFAULT_MAX_TOKENS,
+  type ChatMessage,
+  type LlmClient,
+  type ToolDefinition,
+  type ToolExecutor,
+  type WireMessage,
+} from './llm';
 import { ADVISOR_MARKER } from './stub';
 
 const VALID_EVENT_TYPES = new Set<string>(EVENT_TYPES);
@@ -30,13 +47,130 @@ const VALID_RELATIONS = new Set<string>(RELATION_STATUSES);
 const VALID_OUTCOMES = new Set<string>(['success', 'failure', 'partial', 'neutral']);
 const VALID_STATS = new Set<string>(['military', 'economy', 'stability', 'population']);
 
+// --- The LLM's getNeighbours tool (v0.21, #16 P2: contiguous region transfers) ---
+
+/**
+ * The single tool the turn loop exposes to the model: the precomputed region
+ * adjacency manifest (public/region-adjacency.json, via the resolver injected
+ * into runTurn). Given a set of region keys it returns the union of their
+ * bordering keys (the queried keys themselves excluded, sorted for
+ * determinism) — so the model can verify that a territory transfer is
+ * *contiguous* (a nation gains a region it already abuts) before committing
+ * it, instead of moving whole countries at a whim.
+ */
+export const GET_NEIGHBOURS_TOOL: ToolDefinition = {
+  type: 'function',
+  function: {
+    name: 'getNeighbours',
+    description:
+      'List the region keys that share a land border with any of the given region keys. ' +
+      'Pass a nation\'s territory keys (or a single region key) to see which regions are ' +
+      'contiguous to it. Use it before transferring territory: a nation can realistically ' +
+      'only gain regions that border its existing territory.',
+    parameters: {
+      type: 'object',
+      properties: {
+        regionKeys: {
+          type: 'array',
+          items: { type: 'string' },
+          description: 'One or more region keys to query (e.g. a gaining nation\'s territory).',
+        },
+      },
+      required: ['regionKeys'],
+      additionalProperties: false,
+    },
+  },
+};
+
+/**
+ * Build the tool executor for the turn loop. Never throws: unknown tool
+ * names, malformed arguments, and unknown region keys all degrade to a safe
+ * response (an error object or an empty list) that the model can recover from.
+ */
+export function makeNeighboursExecutor(
+  getNeighbours: (keys: string[]) => string[],
+  validRegionKeys?: ReadonlySet<string>,
+): ToolExecutor {
+  return (name, args) => {
+    if (name !== GET_NEIGHBOURS_TOOL.function.name) {
+      return JSON.stringify({ error: `unknown tool: ${name}` });
+    }
+    const raw = Array.isArray(args.regionKeys) ? args.regionKeys : [];
+    const keys = raw.filter((k): k is string => typeof k === 'string' && k.length > 0);
+    const valid = validRegionKeys ? keys.filter((k) => validRegionKeys.has(k)) : keys;
+    if (valid.length === 0) return JSON.stringify({ neighbours: [] });
+    return JSON.stringify({ neighbours: getNeighbours(valid) });
+  };
+}
+
+/**
+ * The player's frontier: region keys owned by *other* nations that share a
+ * land border with the player's territory (deduped, sorted — stable order for
+ * the deterministic stub). Computed server-side from the adjacency manifest so
+ * both the LLM (the `frontier` field of the user prompt) and the stub (which
+ * cannot call tools) see the same candidates. Empty when there is no
+ * adjacency data or no controllable border (e.g. the UK in 1939).
+ */
+export function playerFrontier(
+  state: GameState,
+  getNeighbours: (keys: string[]) => string[],
+): string[] {
+  const player = state.nations[state.playerNationId];
+  if (!player || player.territory.length === 0) return [];
+  const playerKeys = new Set(player.territory);
+  const candidates = new Set<string>();
+  for (const key of getNeighbours(player.territory)) {
+    if (!playerKeys.has(key)) candidates.add(key);
+  }
+  if (candidates.size === 0) return [];
+  const frontier: string[] = [];
+  for (const n of Object.values(state.nations)) {
+    if (n.id === state.playerNationId) continue;
+    for (const key of n.territory) {
+      if (candidates.has(key)) {
+        candidates.delete(key);
+        frontier.push(key);
+      }
+    }
+  }
+  return frontier.sort();
+}
+
 // --- Prompt building ----------------------------------------------------------
 
-/** The LLM system prompt: world context + rules + a strict JSON contract. */
-export function buildSystemPrompt(preset: Preset): string {
+/**
+ * The LLM system prompt: world context + rules + a strict JSON contract.
+ * When `withNeighboursTool` is set (the turn runs with the getNeighbours tool
+ * available) the contract gains the contiguity rules for territory transfers
+ * (v0.21, #16 P2): the model may only move regions across a shared border, and
+ * may verify borders with the tool before answering. The contract also
+ * documents the `nationOps` proposal queue (v0.23, #16 P4a) — rename plus the
+ * split/merge shapes applied on player confirm (v0.24, #16 P4b).
+ */
+export function buildSystemPrompt(preset: Preset, withNeighboursTool = false): string {
   const rules = preset.simulationRules
     .map((r) => `- ${r}`)
     .join('\n');
+  const respondLine = withNeighboursTool
+    ? 'You have a getNeighbours tool: given region keys it returns the region keys that border them. You may call it (a few times) to verify land borders before deciding territory transfers. Once done, respond with ONLY a valid JSON object of exactly this shape. No prose, no commentary, no markdown fences, no trailing commas:'
+    : 'Respond with ONLY a valid JSON object of exactly this shape. No prose, no commentary, no markdown fences, no trailing commas:';
+  // (v0.22, #16 P3) No man's land: a region can be left unowned after a war or
+  // cataclysm (the model narrates the cause in "events" and lists the key in
+  // "unowned"); unowned regions can later be re-claimed with an ordinary gain.
+  // The model sees the current no-man's-land keys in the user payload's
+  // "unowned" field and in the "regions" reference table.
+  const noMansLandRule =
+    '- A region key has at most one owner at all times — never assign a key to two nations. After a war or cataclysm a region may be left unowned ("no man\'s land"): list its key in "unowned" and narrate the cause in "events"; it stays unowned (grey on the map) until a nation re-claims it with a "gain". The "unowned" field of the user message lists the regions currently in no man\'s land.';
+  const territoryRules = withNeighboursTool
+    ? [
+        '- Territory changes must be contiguous: a nation may only GAIN region keys that share a land border with a region it already owns (verify with getNeighbours) and may only LOSE region keys it currently owns.',
+        '- The "frontier" field of the user message lists region keys owned by other nations that border the player\'s territory — the natural targets of a player-led conquest this turn.',
+        noMansLandRule,
+      ]
+    : [
+        '- Only change borders when war or a decisive political shift justifies it.',
+        noMansLandRule,
+      ];
   return [
     `WORLD: ${preset.title} — ${preset.startDate}`,
     preset.worldBackground,
@@ -45,7 +179,7 @@ export function buildSystemPrompt(preset: Preset): string {
     rules,
     '',
     'You are the world simulator. You advance the shared world state for ALL nations given the current state and the player\'s move.',
-    'Respond with ONLY a valid JSON object of exactly this shape. No prose, no commentary, no markdown fences, no trailing commas:',
+    respondLine,
     '{',
     '  "date": "YYYY-MM-DD (a few days after the current date)",',
     '  "events": [',
@@ -53,16 +187,29 @@ export function buildSystemPrompt(preset: Preset): string {
     '  ],',
     '  "stateChanges": [{"nation":"<nationId>","stat":"<military|economy|stability|population>","op":"<set|add>","value":<0-100>}],',
     '  "relations": [{"a":"<nationId>","b":"<nationId>","set":"<ally|neutral|rival|hostile|war>"}],',
-    '  "territoryChanges": [{"nation":"<nationId>","gain":["<region key>"],"lose":["<region key>"]}]',
+    '  "territoryChanges": [{"nation":"<nationId>","gain":["<region key>"],"lose":["<region key>"]}],',
+    '  "unowned": ["<region key>"],',
+    '  "nationOps": [',
+    '    {"kind":"rename","nationRef":"<nation id or name>","to":"<new name>"},',
+    '    {"kind":"split","nationRef":"<nation id or name>","parts":[{"name":"<new name>","territory":["<region key>"]}]}',
+    '    {"kind":"merge","nationRefs":["<id>","<id>"],"survivingRef":"<id of the surviving nation>","into":"<new name>"}',
+    '  ],',
+    '  "markers": {"add":[{"type":"<city|factory|army|port|capital|fleet|rocket|gathering>","name":"<short name>","regionKey":"<region key>"}],"remove":["<marker id>"]}',
     '}',
     '',
     'HARD CONSTRAINTS',
     '- Use only nation ids and region keys that exist in the provided state.',
-    '- A region key identifies one sub-region; the "regions" table in the user message maps each key to "<region name> (<parent country ISO_A3>)". Use those keys in territoryChanges.',
+    '- A region key identifies one sub-region; the "regions" table in the user message maps each key to "<region name> (<parent country ISO_A3>)". Use those keys in territoryChanges and unowned.',
+    '- List in "unowned" only region keys that a nation currently owns, and narrate each release in "events".',
+    '- Map markers ("markers") are named points on the map, anchored to a region key you own or that the narrative justifies: a capital (a nation\'s main seat of power — at most one per nation), major cities, factory complexes, army deployments, ports, fleet concentrations, rocket launch sites, or a gathering (a large political/social mass event that can enable a non-military takeover). Use only region keys from the "regions" table, keep each name under 40 characters, and place at most a handful of new markers per turn — only where the narrative justifies it. List a marker id from the user message\'s "markers" field in "remove" when it ceases to exist (a city razed, an army dispersed, a site destroyed).',
+    '- Nation-management ops ("nationOps") are PROPOSALS: they only take effect if the player confirms them afterwards. Propose at most 1-2 per turn, only when the narrative justifies it, and narrate each one in "events".',
+    '- Rename: add {"kind":"rename","nationRef":"<nation id or name>","to":"<new name>"} for a revolution, regime change or reunification that changes a nation\'s name.',
+    '- Split: add {"kind":"split","nationRef":"<nation id or name>","parts":[{"name":"<new name>","territory":["<region key>"]}, ...]} when a state breaks up (dissolution, secession). Use at least 2 parts and assign each of the nation\'s region keys to at most one part — any key you leave unassigned goes to the first part.',
+    '- Merge: add {"kind":"merge","nationRefs":["<id or name>","<id or name>"],"survivingRef":"<id or name of the surviving nation>","into":"<new name>"} when states reunify or one is absorbed. Use at least 2 input nations and "survivingRef" must name one of them — the survivor keeps its id and its stats.',
     '- Prefer 1-4 events per turn; keep each text 1-3 sentences.',
     '- Keep your internal reasoning brief (a few sentences) and go straight to the JSON result; do not over-deliberate or re-derive facts already present in the state.',
     '- Keep every stat value between 0 and 100.',
-    '- Only change borders when war or a decisive political shift justifies it.',
+    ...territoryRules,
     '- If a field is not relevant this turn, set it to an empty array.',
   ].join('\n');
 }
@@ -80,6 +227,28 @@ export function buildUserPrompt(
   state: GameState,
   items: RoundItem[],
   regionReference?: Record<string, string>,
+  /**
+   * The player's frontier: region keys owned by other nations that border the
+   * player's territory (v0.21, #16 P2). Emitted verbatim (even when empty) so
+   * the model — and the deterministic stub, which reads it — see the same
+   * contiguous targets. Omitted entirely when undefined (no adjacency data).
+   */
+  frontier?: string[],
+  /**
+   * (v0.22, #16 P3) Region keys that are currently "no man's land" (released
+   * mid-game — `state.unowned`). Emitted verbatim (even when empty) so the
+   * model knows which unowned regions exist and can be re-claimed this turn.
+   * Omitted entirely when undefined.
+   */
+  noMansLand?: string[],
+  /**
+   * (v0.27, #44) The game's current map markers, as the model sees them:
+   * stable id, type, name, region key and current owner. Emitted verbatim
+   * (even when empty) so the model can reference a marker's id in
+   * `TurnResult.markers.remove` or leave an existing marker untouched.
+   * Omitted entirely when undefined.
+   */
+  markers?: MarkerInfo[],
 ): string {
   const player = state.nations[state.playerNationId];
   const playerName = player?.name ?? state.playerNationId;
@@ -116,6 +285,9 @@ export function buildUserPrompt(
     roundInstruction,
   };
   if (regionReference) payload.regions = regionReference;
+  if (frontier !== undefined) payload.frontier = frontier;
+  if (noMansLand !== undefined) payload.unowned = noMansLand;
+  if (markers !== undefined) payload.markers = markers;
   return JSON.stringify(payload, null, 2);
 }
 
@@ -176,6 +348,53 @@ function str(s: unknown, max = 0): string | null {
   return max ? t.slice(0, max) : t;
 }
 
+/**
+ * Validate a raw (LLM) `nationOps` array into safe {@link NationOp} values
+ * (v0.23, #16 P4a). Defensive like the rest of the parser: entries with an
+ * unknown `kind` or missing/empty required fields are dropped, never throw.
+ * Rename: non-empty `nationRef` + `to` (each capped at 200 chars — resolution
+ * of `nationRef` to a concrete nation happens later, at confirm time). Split:
+ * non-empty `nationRef` + at least one part with a name. Merge: non-empty
+ * `nationRefs` (capped at 20) + `survivingRef` + `into`.
+ */
+export function validateNationOps(raw: unknown): NationOp[] {
+  if (!Array.isArray(raw)) return [];
+  const out: NationOp[] = [];
+  for (const e of raw) {
+    if (!e || typeof e !== 'object') continue;
+    const o = e as Record<string, unknown>;
+    if (o.kind === 'rename') {
+      const nationRef = str(o.nationRef, 200);
+      const to = str(o.to, 200);
+      if (nationRef && to) out.push({ kind: 'rename', nationRef, to });
+    } else if (o.kind === 'split') {
+      const nationRef = str(o.nationRef, 200);
+      const parts = (Array.isArray(o.parts) ? o.parts : [])
+        .filter((p): p is Record<string, unknown> => !!p && typeof p === 'object')
+        .map((p) => {
+          const name = str(p.name, 200);
+          const territory = Array.isArray(p.territory)
+            ? p.territory.filter((k): k is string => typeof k === 'string' && k.trim() !== '')
+            : [];
+          return { name, territory };
+        })
+        .filter((p): p is { name: string; territory: string[] } => p.name !== null);
+      if (nationRef && parts.length > 0) out.push({ kind: 'split', nationRef, parts });
+    } else if (o.kind === 'merge') {
+      const nationRefs = (Array.isArray(o.nationRefs) ? o.nationRefs : [])
+        .map((x) => (typeof x === 'string' ? x.trim().slice(0, 200) : ''))
+        .filter((x) => x !== '')
+        .slice(0, 20);
+      const survivingRef = str(o.survivingRef, 200);
+      const into = str(o.into, 200);
+      if (nationRefs.length > 0 && survivingRef && into) {
+        out.push({ kind: 'merge', nationRefs, survivingRef, into });
+      }
+    }
+  }
+  return out;
+}
+
 /**
  * Validate and normalize an arbitrary parsed object into a safe TurnResult.
  * Ignores unknown/invalid entries; clamps numeric stats to 0-100. Returns null
@@ -190,6 +409,9 @@ export function validateTurnResult(input: unknown): TurnResult | null {
     stateChanges: [],
     relations: [],
     territoryChanges: [],
+    unowned: [],
+    nationOps: [],
+    markers: { add: [], remove: [] },
   };
 
   if (Array.isArray(o.events)) {
@@ -265,12 +487,83 @@ export function validateTurnResult(input: unknown): TurnResult | null {
     }
   }
 
+  // (v0.22, #16 P3) Keys released to "no man's land": deduped, non-empty
+  // strings only (applied later by applyTurnResult against validKeys).
+  if (Array.isArray(o.unowned)) {
+    for (const k of o.unowned) {
+      const s = typeof k === 'string' ? k.trim() : '';
+      if (s && !result.unowned.includes(s)) result.unowned.push(s);
+    }
+  }
+
+  // (v0.23, #16 P4a) Nation-management ops the LLM proposes this turn. These
+  // are NOT applied by the turn — applyTurnResult appends them to the pending
+  // list for the player to confirm/reject.
+  result.nationOps = validateNationOps(o.nationOps);
+
+  // (v0.27, #44) Map-marker ops: new placements (validated here) and
+  // removals by stable id. Applied by applyTurnResult after the territory
+  // moves (a new marker's owner is the region's post-turn owner).
+  result.markers = validateMarkerOps(o.markers);
+
   return result;
 }
 
-/** A turn is "meaningful" if it produced at least an event or a stat change. */
+/**
+ * (v0.27, #44) Validate the raw `markers` object of a turn into a safe
+ * `{ add, remove }` shape. Defensive like the rest of the parser — never
+ * throws. `add`: each spec needs a known marker type, a non-empty `name`
+ * (capped at 120 chars) and a non-empty `regionKey` (capped at 120 chars);
+ * specs whose derived id collides with an earlier one in the same batch
+ * collapse to the first (re-adding is idempotent). `remove`: deduped,
+ * non-empty marker ids (capped at 120 chars).
+ */
+export function validateMarkerOps(raw: unknown): { add: MarkerSpec[]; remove: string[] } {
+  const out: { add: MarkerSpec[]; remove: string[] } = { add: [], remove: [] };
+  if (!raw || typeof raw !== 'object' || Array.isArray(raw)) return out;
+  const o = raw as Record<string, unknown>;
+  if (Array.isArray(o.add)) {
+    const seen = new Set<string>();
+    for (const e of o.add) {
+      if (!e || typeof e !== 'object') continue;
+      const s = e as Record<string, unknown>;
+      if (!isMarkerType(s.type)) continue;
+      const name = str(s.name, 120);
+      const regionKey = str(s.regionKey, 120);
+      if (!name || !regionKey) continue;
+      const id = markerId(s.type, name, regionKey);
+      if (seen.has(id)) continue;
+      seen.add(id);
+      out.add.push({ type: s.type, name, regionKey });
+    }
+  }
+  if (Array.isArray(o.remove)) {
+    for (const k of o.remove) {
+      const s = typeof k === 'string' ? k.trim() : '';
+      if (s && !out.remove.includes(s)) out.remove.push(s.slice(0, 120));
+    }
+  }
+  return out;
+}
+
+/**
+ * A turn is "meaningful" if it produced at least an event, a stat change, a
+ * no-man's-land release (v0.22 #16 P3: a release is a real world change even
+ * when the model under-narrates it), or a nation-op proposal (v0.23 #16 P4a:
+ * a proposal is a real pending-world change the player will resolve, so it
+ * must survive the retry/nudge path instead of being replaced by the generic
+ * "unclear" result).
+ */
 export function isMeaningful(result: TurnResult): boolean {
-  return result.events.length > 0 || result.stateChanges.length > 0;
+  return (
+    result.events.length > 0 ||
+    result.stateChanges.length > 0 ||
+    result.unowned.length > 0 ||
+    result.nationOps.length > 0 ||
+    // (v0.27, #44) a marker placed or removed this turn is a real world change.
+    result.markers.add.length > 0 ||
+    result.markers.remove.length > 0
+  );
 }
 
 // --- Applying the delta -------------------------------------------------------
@@ -287,9 +580,25 @@ function genericUnclearEvent(state: GameState): TurnEventSpec {
 
 /**
  * Apply a TurnResult to a GameState immutably: advance the date/turn, append
- * events, apply stat changes (clamped), symmetric relations, and territory moves.
+ * events, apply stat changes (clamped), symmetric relations, territory moves
+ * (including no-man's-land releases, v0.22 #16 P3) and map markers (v0.27
+ * #44). It also appends any proposed nation-ops to the pending list (v0.23
+ * #16 P4a) without applying them — see the doc comment on `pendingNationOps`
+ * for why that list deliberately survives across turns.
+ *
+ * `centroidOf` (v0.27, #44) resolves a region key to its precomputed centroid
+ * (`{ lat, lon, spread }`, from public/region-centroids.json via
+ * server/regions.ts). New markers are positioned at that centroid plus a small
+ * deterministic offset; a spec whose key has no known centroid is dropped.
+ * Without it no marker can be placed (all adds are dropped), which keeps the
+ * engine pure and lets tests inject their own data.
  */
-export function applyTurnResult(state: GameState, result: TurnResult, validKeys?: ReadonlySet<string>): GameState {
+export function applyTurnResult(
+  state: GameState,
+  result: TurnResult,
+  validKeys?: ReadonlySet<string>,
+  centroidOf?: (key: string) => { lat: number; lon: number; spread: number } | undefined,
+): GameState {
   const next: GameState = JSON.parse(JSON.stringify(state));
   next.version = (state.version ?? 0) + 1; // every mutation is a new revision
   const actingTurn = state.turn; // this action resolves the current turn
@@ -312,24 +621,171 @@ export function applyTurnResult(state: GameState, result: TurnResult, validKeys?
     a.relations[r.b] = r.set;
     b.relations[r.a] = r.set;
   }
-  for (const t of result.territoryChanges) {
-    const n = next.nations[t.nation];
-    if (!n) continue;
-    const valid = (k: string) => !validKeys || validKeys.has(k);
-    for (const key of t.gain) {
-      if (!valid(key)) continue; // ignore a key that is not a real region
-      for (const other of Object.values(next.nations)) {
-        const i = other.territory.indexOf(key);
-        if (i !== -1) other.territory.splice(i, 1);
-      }
-      if (!n.territory.includes(key)) n.territory.push(key);
-    }
-    for (const key of t.lose) {
+  // --- Territory (v0.21, #16 P2: at most one owner per key;
+  //     v0.22, #16 P3: a key may also be released to "no man's land") ---
+  //
+  // Two kinds of change, applied in this order:
+  //
+  //  (1) RELEASES (`result.unowned`, v0.22 #16 P3): each key that a nation
+  //      CURRENTLY owns (exactly one owner) is removed from that owner, left
+  //      ownerless, and added to `GameState.unowned` — the client renders it
+  //      as the distinct no-man's-land grey. A key with zero owners (a preset
+  //      never assigned it) is never released: doing so would fabricate a
+  //      visible no-man's-land out of an ordinary unowned region. A key with
+  //      two or more owners (pre-existing corruption) is never touched, and
+  //      a key already in `unowned` is a no-op (it is already unowned).
+  //
+  //  (2) CLAIMS (`gain` entries), resolved against the ownership AFTER the
+  //      releases (snapshot-first):
+  //      - a key with exactly one owner that is not the gainer → a TRANSFER:
+  //        removed from the old owner, granted to the gainer (v0.21 rules);
+  //      - a key with NO owner → a RE-CLAIM: granted to the (sole) gainer and
+  //        removed from `GameState.unowned` (it leaves no man's land);
+  //      - a double claim (two or more distinct gainers) is rejected — the
+  //        key stays as it is; a self-gain is a no-op; a pre-existing double
+  //        ownership is never touched.
+  //
+  // Invariants after the turn: no key sits in two or more territories; a
+  // released key sits in none; `GameState.unowned` holds exactly the
+  // zero-owner keys that were released mid-game (not the preset-unassigned
+  // ones). "lose" entries remain deliberate no-ops: releasing is the
+  // `unowned` list's job, and a lone loss without a release would just
+  // orphan a key silently.
+  const valid = (k: string) => !validKeys || validKeys.has(k);
+  const unowned = new Set(state.unowned ?? []);
+
+  // (1) Releases: establish the new no-man's-land set before any claim.
+  for (const key of new Set(result.unowned)) {
+    if (!valid(key) || unowned.has(key)) continue;
+    const owners = Object.values(next.nations)
+      .filter((n) => n.territory.includes(key))
+      .map((n) => n.id);
+    if (owners.length !== 1) continue; // 0 owners (never assigned) or 2+ (corrupt): no-op
+    unowned.add(key);
+    next.nations[owners[0]].territory = next.nations[owners[0]].territory.filter((k) => k !== key);
+  }
+
+  // (2) Claims against the post-release ownership snapshot.
+  const ownerOf = new Map<string, string>(); // key -> sole owner id, or '' (2+ owners; 0 = absent)
+  for (const n of Object.values(next.nations)) {
+    for (const key of n.territory) {
       if (!valid(key)) continue;
+      const cur = ownerOf.get(key);
+      if (cur === undefined) ownerOf.set(key, n.id);
+      else if (cur !== '') ownerOf.set(key, '');
+    }
+  }
+  // Claim pairs, deduped: one (key, gainer) per pair even if the model emits
+  // duplicate entries; two DIFFERENT gainers for one key is a double claim.
+  const claimPairs = new Set<string>();
+  for (const t of result.territoryChanges) {
+    if (!next.nations[t.nation]) continue;
+    for (const key of new Set(t.gain)) {
+      if (!valid(key)) continue;
+      claimPairs.add(`${key}\u0000${t.nation}`);
+    }
+  }
+  const claimants = new Map<string, Set<string>>(); // key -> distinct gainers
+  for (const pair of claimPairs) {
+    const idx = pair.indexOf('\u0000');
+    const key = pair.slice(0, idx);
+    const gainer = pair.slice(idx + 1);
+    let set = claimants.get(key);
+    if (set === undefined) {
+      set = new Set();
+      claimants.set(key, set);
+    }
+    set.add(gainer);
+  }
+  for (const [key, claiming] of claimants) {
+    if (claiming.size !== 1) continue; // double claim: the key stays as it was
+    const gainer = [...claiming][0];
+    const owner = ownerOf.get(key); // undefined: no owner; '': 2+ owners (corrupt)
+    if (owner === '') continue; // pre-existing double ownership: never touched
+    if (owner !== undefined && owner === gainer) continue; // self-gain: no-op
+    for (const n of Object.values(next.nations)) {
       const i = n.territory.indexOf(key);
       if (i !== -1) n.territory.splice(i, 1);
     }
+    next.nations[gainer].territory.push(key);
+    unowned.delete(key); // re-claimed: the key leaves no man's land
   }
+
+  next.unowned = [...unowned];
+
+  // --- Map markers (v0.27, #44) ---
+  //
+  // Markers are anchored to a region key and are processed against the FINAL
+  // post-claim ownership, in this order:
+  //   (1) REMOVE: a marker whose id is in result.markers.remove is dropped
+  //       (a listed-but-absent id is a no-op).
+  //   (2) OWNER RECOMPUTE: every surviving marker's ownerNationId is set to
+  //       its region's current owner — a captured region follows the new
+  //       owner, a region released to no man's land (or a key with 0 or 2+
+  //       owners) becomes `null`. A marker always follows its region.
+  //   (3) ADD: each new spec (in order) is placed at its region's centroid
+  //       (injected via centroidOf) plus a small deterministic per-axis
+  //       offset, owned by the region's post-turn owner, and stamped with
+  //       the acting turn. Dropped (never throws): a region key that is not
+  //       in validKeys or has no known centroid, an id that already exists
+  //       (a re-add is idempotent — the existing marker stays), and any adds
+  //       beyond MAX_MARKERS (the later ones).
+  {
+    const finalOwner = new Map<string, string | null>();
+    {
+      const owners = new Map<string, string[]>();
+      for (const n of Object.values(next.nations)) {
+        for (const key of n.territory) {
+          if (!valid(key)) continue;
+          const list = owners.get(key);
+          if (list) list.push(n.id);
+          else owners.set(key, [n.id]);
+        }
+      }
+      for (const [key, list] of owners) finalOwner.set(key, list.length === 1 ? list[0] : null);
+    }
+    const removeIds = new Set(result.markers.remove);
+    const markers: MapMarker[] = [];
+    for (const m of next.markers ?? []) {
+      if (removeIds.has(m.id)) continue;
+      markers.push({ ...m, ownerNationId: finalOwner.get(m.regionKey) ?? null });
+    }
+    // Deterministic ±(spread/2) offset per axis: a FNV-1a-derived unit
+    // fraction of the marker id (stable across runs and platforms), so
+    // markers of one region scatter naturally instead of stacking.
+    const jitter = (id: string, axis: 'lat' | 'lon', spread: number): number => {
+      const frac = (fnv1a32(`${id}#${axis}`) >>> 8) / 0x00ffffff;
+      return (frac * 2 - 1) * (spread / 2);
+    };
+    const round6 = (v: number): number => Math.round(v * 1e6) / 1e6;
+    for (const spec of result.markers.add) {
+      const id = markerId(spec.type, spec.name, spec.regionKey);
+      if (markers.some((m) => m.id === id)) continue; // re-add: idempotent, keep the existing
+      if (markers.length >= MAX_MARKERS) continue; // hard cap: drop the excess
+      if (!valid(spec.regionKey)) continue; // unknown region key
+      const c = centroidOf?.(spec.regionKey);
+      if (!c) continue; // no centroid data for this key
+      markers.push({
+        id,
+        type: spec.type,
+        name: spec.name,
+        regionKey: spec.regionKey,
+        lat: round6(c.lat + jitter(id, 'lat', c.spread)),
+        lon: round6(c.lon + jitter(id, 'lon', c.spread)),
+        ownerNationId: finalOwner.get(spec.regionKey) ?? null,
+        placedTurn: actingTurn,
+      });
+    }
+    next.markers = markers;
+  }
+
+  // (v0.23, #16 P4a) Nation-op proposals are NOT applied by the turn — they
+  // are appended to the pending list, which (unlike `pending`) SURVIVES
+  // across turns until the player confirms or rejects each one. `next` is a
+  // deep clone of `state`, so `next.pendingNationOps` is a copy of whatever
+  // the state already held (or undefined for a legacy row) — start from that
+  // and append the new proposals, defaulting a missing field to `[]`.
+  next.pendingNationOps = [...(next.pendingNationOps ?? []), ...result.nationOps];
   return next;
 }
 
@@ -364,12 +820,278 @@ export function removeRoundItem(state: GameState, index: number | undefined): Ga
   return next;
 }
 
+// --- Nation-management ops (v0.23, #16 P4a: the hybrid "LLM proposes,
+// player confirms" model) ----------------------------------------------------
+//
+// A NationOp proposed by a turn lands in `GameState.pendingNationOps` (see
+// applyTurnResult) and waits there across turns. These functions resolve the
+// player's decision on one pending proposal, by index. Like removeRoundItem
+// they are pure: clone the state, mutate the clone, bump `version` once,
+// return the new state — and return `null` for a bad index so the route can
+// answer 400 without mutating anything.
+
+/** True when `index` is a valid, in-bounds integer position in the pending list. */
+function validPendingOpIndex(state: GameState, index: number): boolean {
+  const len = state.pendingNationOps?.length ?? 0;
+  return Number.isInteger(index) && index >= 0 && index < len;
+}
+
 /**
- * Run one turn end-to-end against the (injectable) LLM: build prompts, call the
- * model ONCE over the whole pending batch, parse/validate, retry once with a
- * nudge if the result is empty/invalid, and — if it is still invalid — emit a
- * generic "unclear" event and advance. The committed state has `pending` cleared.
- * Never throws on bad model output; only the underlying transport/network can throw.
+ * Resolve a nation reference (the `nationRef` of a NationOp — the LLM may
+ * write either the nation's stable `id` or its human-readable `name`) to a
+ * concrete nation id: an exact id match wins, then a unique case-insensitive
+ * name match. Returns `null` when the reference is empty, unknown, or
+ * ambiguous (two or more nations share that name) — every caller treats
+ * `null` as "no-op" and nothing here ever throws.
+ */
+export function resolveNationRef(state: GameState, ref: string): string | null {
+  const r = (ref ?? '').trim();
+  if (!r) return null;
+  if (state.nations[r]) return r; // exact id first
+  const matches = Object.values(state.nations).filter(
+    (n) => n.name.trim().toLowerCase() === r.toLowerCase(),
+  );
+  return matches.length === 1 ? matches[0].id : null;
+}
+
+/**
+ * Generate a fresh, unused nation id for a newly created nation (split
+ * parts, v0.24 #16 P4b): the first free of `n1`, `n2`, ... The caller adds
+ * each id it creates to `taken` as it goes, so ids stay unique within an
+ * op and are never reused from a removed nation.
+ */
+export function freshNationId(taken: ReadonlySet<string>): string {
+  for (let i = 1; ; i++) {
+    const id = `n${i}`;
+    if (!taken.has(id)) return id;
+  }
+}
+
+/**
+ * The baseline stats a freshly created nation starts with (split parts,
+ * v0.24 #16 P4b) — a neutral middle-of-the-scale profile, deliberately NOT
+ * a copy of the parent's stats (a small rump state is not the parent's
+ * military power).
+ */
+export const NEW_NATION_STATS: NationStats = {
+  military: 50,
+  economy: 50,
+  stability: 50,
+  population: 50,
+};
+
+/**
+ * Defensive cleanup after nations are removed (merge, v0.24 #16 P4b): drop
+ * the removed nations' ids from every remaining nation's `relations` map so
+ * no key dangles. (The client already degrades gracefully on a missing
+ * target, but consistent data is cleaner.)
+ */
+function dropRelationsTo(state: GameState, removedIds: ReadonlySet<string>): void {
+  for (const n of Object.values(state.nations)) {
+    for (const id of removedIds) {
+      if (id in n.relations) delete n.relations[id];
+    }
+  }
+}
+
+/**
+ * Apply one NationOp to a state, MUTATING the passed object in place (the
+ * caller passes a clone — confirmNationOp does) and NOT bumping `version`
+ * (the route-level functions do that once per decision). It never throws:
+ * any unresolvable reference or malformed op is a silent no-op (the op is
+ * still removed by confirmNationOp — the world simply doesn't change).
+ *
+ *  - **rename** (v0.23, #16 P4a): changes only `Nation.name` — the id, its
+ *    territory, its relations (keyed by id), and the player pointer all stay
+ *    valid, so nothing downstream breaks; a player-supplied `edits.name`
+ *    overrides the proposed `to` (an empty edit falls back to the proposal's
+ *    own name).
+ *
+ *  - **split** (v0.24, #16 P4b): the `nationRef` must resolve and there must
+ *    be at least two named parts, else no-op. Parts are processed in order;
+ *    each receives the region keys of its `territory` that (a) the parent
+ *    owns and (b) no earlier part claimed — the first part to name a key
+ *    wins. Keys of the parent's territory that no part claimed go to part 0
+ *    (in the parent's `territory` order), so the parent's territory is fully
+ *    partitioned — no key is lost or ever held twice. Each part gets a
+ *    FRESH id (`freshNationId`) and the baseline `NEW_NATION_STATS` (not a
+ *    copy of the parent's), plus a copy of the parent's relations; the
+ *    parent is then removed. If the parent was the player's nation,
+ *    `playerNationId` moves to the chosen part (`edits.playerPart`, clamped
+ *    into range, default 0); `edits.name` renames that same chosen part.
+ *
+ *  - **merge** (v0.24, #16 P4b): every input ref plus the survivor ref must
+ *    resolve, at least two inputs must resolve to DISTINCT nations, and the
+ *    survivor must be one of them — else no-op. The survivor keeps its id,
+ *    keeps its own stats, gains the union of all inputs' territories
+ *    (survivor's keys first, then each other input's unclaimed keys in its
+ *    own order), and gains a union of the inputs' relations (on a third
+ *    party the survivor's own view wins, else the first input's). The other
+ *    inputs are removed (their ids dropped from everyone else's relations
+ *    maps), and if the player led a removed input, `playerNationId` moves to
+ *    the survivor. The merged name is `edits.name` (if non-empty), else
+ *    `op.into`, else the survivor's current name.
+ */
+export function applyNationOp(
+  state: GameState,
+  op: NationOp,
+  edits?: { name?: string; playerPart?: number },
+): void {
+  if (op.kind === 'rename') {
+    const id = resolveNationRef(state, op.nationRef);
+    if (id === null) return; // invalid/ambiguous ref: no-op
+    const n = state.nations[id];
+    if (!n) return;
+    const name = (edits?.name ?? '').trim() || op.to.trim();
+    if (name) n.name = name;
+    return;
+  }
+
+  if (op.kind === 'split') {
+    const id = resolveNationRef(state, op.nationRef);
+    if (id === null || op.parts.length < 2) return; // invalid ref / not enough parts: no-op
+    const parent = state.nations[id];
+    if (!parent) return;
+    const taken = new Set(Object.keys(state.nations));
+    const created: string[] = [];
+    const claimed = new Set<string>();
+    for (const part of op.parts) {
+      const newId = freshNationId(taken);
+      taken.add(newId);
+      const keys = (part.territory ?? [])
+        .filter((k) => parent.territory.includes(k) && !claimed.has(k));
+      for (const k of keys) claimed.add(k);
+      const partNation: Nation = {
+        id: newId,
+        type: parent.type, // a part keeps the parent's form of state
+        name: part.name,
+        stats: { ...NEW_NATION_STATS },
+        territory: keys,
+        relations: { ...parent.relations },
+      };
+      state.nations[newId] = partNation;
+      created.push(newId);
+    }
+    // Keys the parent owned but no part claimed go to part 0 (in the
+    // parent's territory order) — nothing is lost or duplicated.
+    for (const k of parent.territory) {
+      if (!claimed.has(k)) state.nations[created[0]].territory.push(k);
+    }
+    // The player chooses which part is its successor (edits.playerPart,
+    // clamped into range; default 0) — only relevant when the parent was
+    // the player's nation; the same part also gets a player-edited name.
+    const partIdx =
+      Math.min(Math.max(edits?.playerPart ?? 0, 0), created.length - 1);
+    if (state.playerNationId === id) state.playerNationId = created[partIdx];
+    const editedName = (edits?.name ?? '').trim();
+    if (editedName) state.nations[created[partIdx]].name = editedName;
+    delete state.nations[id];
+    dropRelationsTo(state, new Set([id]));
+    return;
+  }
+
+  // merge
+  const resolved: string[] = [];
+  for (const ref of op.nationRefs) {
+    const rid = resolveNationRef(state, ref);
+    if (rid === null) return; // any unresolvable input: no-op
+    resolved.push(rid);
+  }
+  const inputIds = new Set(resolved);
+  const survivorId = resolveNationRef(state, op.survivingRef);
+  if (survivorId === null || !inputIds.has(survivorId) || inputIds.size < 2) return;
+  const survivor = state.nations[survivorId];
+  if (!survivor) return;
+  // Territory: the union of all inputs — the survivor's keys first (stable
+  // order), then each other input's unclaimed keys in its own order.
+  const territory = [...survivor.territory];
+  const seen = new Set(territory);
+  for (const rid of resolved) {
+    for (const k of state.nations[rid].territory) {
+      if (!seen.has(k)) {
+        seen.add(k);
+        territory.push(k);
+      }
+    }
+  }
+  // Relations: the union of all inputs' relations; the first input to name a
+  // third party sets it, then the survivor's own view overwrites per key.
+  const relations: Record<string, RelationStatus> = {};
+  for (const rid of resolved) {
+    for (const [other, status] of Object.entries(state.nations[rid].relations)) {
+      if (other === survivorId) continue; // never relate to oneself
+      if (!(other in relations)) relations[other] = status;
+    }
+  }
+  for (const [other, status] of Object.entries(survivor.relations)) {
+    if (other !== survivorId) relations[other] = status;
+  }
+  const removed = new Set<string>();
+  for (const rid of inputIds) {
+    if (rid === survivorId) continue;
+    delete state.nations[rid];
+    removed.add(rid);
+  }
+  if (state.playerNationId !== survivorId && removed.has(state.playerNationId)) {
+    state.playerNationId = survivorId;
+  }
+  const name = (edits?.name ?? '').trim() || op.into.trim() || survivor.name;
+  if (name) survivor.name = name;
+  survivor.territory = territory;
+  survivor.relations = relations;
+  dropRelationsTo(state, removed);
+}
+
+/**
+ * Confirm a pending nation-op proposal by index: apply it (a rename takes
+ * effect, optionally with a player-edited name; a split partitions the
+ * nation's territory into the new parts, the player picking which part is
+ * its successor via `edits.playerPart`; a merge folds the inputs into the
+ * survivor, optionally renamed via `edits.name`) and remove it from
+ * `pendingNationOps`, bumping `version`. Returns `null` for an invalid
+ * index, so the route answers 400 without mutating. Reused by the
+ * /nation-op/confirm route.
+ */
+export function confirmNationOp(
+  state: GameState,
+  index: number,
+  edits?: { name?: string; playerPart?: number },
+): GameState | null {
+  if (!validPendingOpIndex(state, index)) return null;
+  const next: GameState = JSON.parse(JSON.stringify(state));
+  next.version = (state.version ?? 0) + 1;
+  const op = next.pendingNationOps[index];
+  applyNationOp(next, op, edits);
+  next.pendingNationOps.splice(index, 1);
+  return next;
+}
+
+/**
+ * Reject (drop) a pending nation-op proposal by index without applying it,
+ * bumping `version`. Returns `null` for an invalid index, so the route
+ * answers 400 without mutating. Reused by the /nation-op/reject route.
+ */
+export function rejectNationOp(state: GameState, index: number): GameState | null {
+  if (!validPendingOpIndex(state, index)) return null;
+  const next: GameState = JSON.parse(JSON.stringify(state));
+  next.version = (state.version ?? 0) + 1;
+  next.pendingNationOps.splice(index, 1);
+  return next;
+}
+
+/**
+ * Run one turn end-to-end against the (injectable) LLM: build prompts, parse/
+ * validate, retry once with a nudge if the result is empty/invalid, and — if
+ * it is still invalid — emit a generic "unclear" event and advance. The
+ * committed state has `pending` cleared. Never throws on bad model output;
+ * only the underlying transport/network can throw.
+ *
+ * When `getNeighbours` is provided AND the LLM client implements
+ * `chatWithTools` (v0.21, #16 P2), the turn runs the bounded function-
+ * calling loop with the getNeighbours tool (the model may verify land
+ * borders before committing a territory transfer) and the user prompt gains
+ * the player's `frontier` field. Otherwise it falls back to a plain chat()
+ * call — same as before the tool existed.
  */
 export async function runTurn(opts: {
   llm: LlmClient;
@@ -380,25 +1102,70 @@ export async function runTurn(opts: {
   regionReference?: Record<string, string>;
   /** Set of valid region keys; territory changes with other keys are ignored. */
   validRegionKeys?: ReadonlySet<string>;
+  /**
+   * Region adjacency resolver (keys -> bordering keys, from the precomputed
+   * manifest). Its presence (together with the client's chatWithTools)
+   * switches the turn onto the getNeighbours tool path.
+   */
+  getNeighbours?: (keys: string[]) => string[];
+  /**
+   * (v0.27, #44) Region-key -> precomputed centroid resolver (from
+   * public/region-centroids.json). Present, the turn's new markers can be
+   * placed at their region's centroid; absent, marker adds are dropped and
+   * the existing markers' owners still get recomputed.
+   */
+  centroidOf?: (key: string) => { lat: number; lon: number; spread: number } | undefined;
 }): Promise<{ state: GameState; result: TurnResult }> {
-  const { llm, preset, state, items, regionReference, validRegionKeys } = opts;
-  const system = buildSystemPrompt(preset);
-  const user = buildUserPrompt(state, items, regionReference);
+  const { llm, preset, state, items, regionReference, validRegionKeys, getNeighbours, centroidOf } = opts;
+  const chatWithTools = llm.chatWithTools;
+  const useTools = getNeighbours !== undefined && chatWithTools !== undefined;
+  const system = buildSystemPrompt(preset, useTools);
+  const frontier = getNeighbours ? playerFrontier(state, getNeighbours) : undefined;
+  // (v0.22, #16 P3) the model always sees the current no-man's-land keys (empty
+  // list on a fresh game) so it knows which unowned regions can be re-claimed.
+  // (v0.27, #44) likewise the current map markers, so it can reference their
+  // stable ids in `markers.remove` (or leave them untouched).
+  const markers = (state.markers ?? []).map((m) => ({
+    id: m.id,
+    type: m.type,
+    name: m.name,
+    regionKey: m.regionKey,
+    owner: m.ownerNationId,
+  }));
+  const user = buildUserPrompt(state, items, regionReference, frontier, state.unowned ?? [], markers);
   const nudge =
     'Your previous output was invalid. Respond with ONLY the JSON object described above for this batch — no prose, no fences.';
 
-  let result = parseTurnResult(await llm.chat([
+  /**
+   * One model call with the standard turn sampling: the bounded
+   * function-calling loop when available, else a plain chat(). The nudge
+   * re-send below always starts a FRESH history (no tool context carried
+   * over).
+   */
+  const call = async (history: WireMessage[]): Promise<string> => {
+    if (useTools) {
+      return await chatWithTools(
+        history,
+        [GET_NEIGHBOURS_TOOL],
+        makeNeighboursExecutor(getNeighbours, validRegionKeys),
+        { temperature: 0.4, maxTokens: DEFAULT_MAX_TOKENS },
+      );
+    }
+    return llm.chat(history as ChatMessage[], { temperature: 0.4, maxTokens: DEFAULT_MAX_TOKENS });
+  };
+
+  let result = parseTurnResult(await call([
     { role: 'system', content: system },
     { role: 'user', content: user },
-  ], { temperature: 0.4, maxTokens: DEFAULT_MAX_TOKENS }));
+  ]));
 
   if (result === null || !isMeaningful(result)) {
-    result = parseTurnResult(await llm.chat([
+    result = parseTurnResult(await call([
       { role: 'system', content: system },
       { role: 'user', content: user },
       { role: 'assistant', content: '' },
       { role: 'user', content: nudge },
-    ], { temperature: 0.4, maxTokens: DEFAULT_MAX_TOKENS }));
+    ]));
   }
 
   if (result === null || !isMeaningful(result)) {
@@ -408,10 +1175,13 @@ export async function runTurn(opts: {
       stateChanges: [],
       relations: [],
       territoryChanges: [],
+      unowned: [],
+      nationOps: [],
+      markers: { add: [], remove: [] },
     };
   }
 
-  return { state: applyTurnResult(state, result, validRegionKeys), result };
+  return { state: applyTurnResult(state, result, validRegionKeys, centroidOf), result };
 }
 
 // --- Advisor (brainstorm) -----------------------------------------------------

server/index.ts

@@ -12,15 +12,17 @@ import { deepClone } from '../shared/protocol';
 import type {
   AddActionRequest,
   AddDiplomacyRequest,
+  ConfirmNationOpRequest,
   CreateGameRequest,
+  RejectNationOpRequest,
   RemoveQueueItemRequest,
 } from '../shared/protocol';
 import type { GameState } from '../shared/types';
 import { createLlmClient } from './llm';
 import { makeStubLlmClient } from './stub';
-import { askAdvisor, queueRoundItem, removeRoundItem, runTurn } from './engine';
+import { askAdvisor, confirmNationOp, queueRoundItem, rejectNationOp, removeRoundItem, runTurn } from './engine';
 import { buildRegionMap } from './map';
-import { allTerritoryKeys, expandCountriesToKeys, loadRegions, referenceForKeys, validKeys } from './regions';
+import { allTerritoryKeys, centroidOf, expandCountriesToKeys, hasAdjacency, hasCentroids, loadRegions, neighboursOf, referenceForKeys, validKeys } from './regions';
 import { createPresetStore } from './presets';
 import { openDb, type Db } from './db';
 
@@ -124,6 +126,16 @@ app.post('/api/games', (req: Request, res) => {
     events: [],
     pending: [],
     version: 1, // the first saved revision; every later mutation bumps it
+    // (v0.22, #16 P3) No man's land can only arise mid-game — a fresh game
+    // starts with nothing released; this list grows as the LLM releases
+    // regions and shrinks as they get re-claimed.
+    unowned: [],
+    // (v0.23, #16 P4a) No pending nation-op proposals on a fresh game; the
+    // list grows as the LLM proposes renames (and, later, splits/merges) and
+    // shrinks as the player confirms or rejects them.
+    pendingNationOps: [],
+    // (v0.27, #44) No markers on a fresh game; the LLM places them over time.
+    markers: [],
   };
   // v0.19 (#16 P1): expand each nation's ISO_A3 country list to the region keys
   // of all its sub-regions, so ownership (and the choropleth) is at region
@@ -220,6 +232,38 @@ app.post('/api/games/:id/queue/remove', (req, res) => {
   res.json({ game: next });
 });
 
+// (v0.23, #16 P4a; v0.24, #16 P4b) Resolve a pending nation-op proposal
+// waiting in game.pendingNationOps: a rename takes effect (body.edits.name
+// may override the proposed name), a split partitions the nation's territory
+// into the proposed parts (body.edits.playerPart picks which part the player
+// leads, default 0), and a merge folds its inputs into the survivor
+// (body.edits.name may override the merged name). No LLM call, no turn
+// advance — same fast save → broadcast → respond order as /queue/remove.
+// The version bump lets "never go backwards" clients reconcile.
+app.post('/api/games/:id/nation-op/confirm', (req, res) => {
+  const id = req.params.id;
+  const game = db.load(id);
+  if (!game) return res.status(404).json({ error: 'game not found' });
+  const body = (req.body ?? {}) as ConfirmNationOpRequest;
+  const next = confirmNationOp(game, body.index, body.edits);
+  if (!next) return res.status(400).json({ error: 'invalid proposal index' });
+  db.save(next);
+  broadcast(id, 'state', { state: next });
+  res.json({ game: next });
+});
+
+app.post('/api/games/:id/nation-op/reject', (req, res) => {
+  const id = req.params.id;
+  const game = db.load(id);
+  if (!game) return res.status(404).json({ error: 'game not found' });
+  const body = (req.body ?? {}) as RejectNationOpRequest;
+  const next = rejectNationOp(game, body.index);
+  if (!next) return res.status(400).json({ error: 'invalid proposal index' });
+  db.save(next);
+  broadcast(id, 'state', { state: next });
+  res.json({ game: next });
+});
+
 // Jump forward: commit the whole pending round (or an empty one) to the model
 // in a single turn. applyTurnResult clears the pending queue on the returned
 // state. 404 for not-found/preset-missing; 502 for LLM/model (transport) errors.
@@ -235,8 +279,22 @@ app.post('/api/games/:id/jump', async (req, res) => {
       preset,
       state: game,
       items: game.pending,
-      regionReference: referenceForKeys(allTerritoryKeys(game)),
+      // (v0.22, #16 P3) the region reference table must also cover released
+      // (no-man's-land) keys — they belong to no nation's territory, but the
+      // model needs their names to re-claim them.
+      regionReference: referenceForKeys(
+        new Set([...allTerritoryKeys(game), ...(game.unowned ?? [])]),
+      ),
       validRegionKeys: validKeys(),
+      // v0.21 (#16 P2): when the region-adjacency manifest loaded, hand the
+      // engine the resolver — the turn then runs with the LLM's getNeighbours
+      // tool and the player-frontier prompt field (both switch off without it).
+      getNeighbours: hasAdjacency() ? (keys) => neighboursOf(keys) : undefined,
+      // (v0.27, #44) when the centroid manifest loaded, hand the engine the
+      // resolver so a turn can place new map markers at their region's
+      // centroid (without it, marker adds are dropped; existing markers are
+      // still maintained).
+      centroidOf: hasCentroids() ? (key) => centroidOf(key) : undefined,
     });
     db.save(state);
     broadcast(id, 'turn', { state, result });

server/llm.test.ts

@@ -208,3 +208,182 @@ describe('createLlmClient (injectable transport)', () => {
     );
   });
 });
+
+describe('createLlmClient.chatWithTools (function-calling loop, v0.21 #16 P2)', () => {
+  const tool = {
+    type: 'function' as const,
+    function: {
+      name: 'getNeighbours',
+      description: 'list bordering region keys',
+      parameters: { type: 'object' },
+    },
+  };
+
+  function toolCallResponse(id: string, name: string, args: string) {
+    return json({
+      choices: [
+        {
+          finish_reason: 'tool_calls',
+          message: {
+            content: null,
+            tool_calls: [{ id, type: 'function', function: { name, arguments: args } }],
+          },
+        },
+      ],
+    });
+  }
+
+  function contentResponse(content: string) {
+    return json({ choices: [{ finish_reason: 'stop', message: { content } }] });
+  }
+
+  it('sends tools in the first request; echoes the assistant tool_calls + tool result; the executor gets parsed args', async () => {
+    const sent: string[] = [];
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      if (sent.length === 1) return toolCallResponse('call_1', 'getNeighbours', '{"regionKeys":["a"]}');
+      return contentResponse('final answer');
+    };
+    const executorCalls: Array<{ name: string; args: Record<string, unknown> }> = [];
+    const llm = createLlmClient({ transport, apiBase: 'http://x/v1', model: 'm' });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      (name, args) => {
+        executorCalls.push({ name, args });
+        return JSON.stringify({ neighbours: ['b'] });
+      },
+    );
+    expect(out).toBe('final answer');
+    expect(sent).toHaveLength(2);
+    // request 1: the tools array is present, history is just the initial message
+    const body1 = JSON.parse(sent[0]);
+    expect(body1.tools).toEqual([tool]);
+    expect(body1.messages).toEqual([{ role: 'user', content: 'hi' }]);
+    // request 2: the assistant tool-call and the tool result are echoed back
+    const body2 = JSON.parse(sent[1]);
+    expect(body2.tools).toEqual([tool]);
+    expect(body2.messages).toEqual([
+      { role: 'user', content: 'hi' },
+      {
+        role: 'assistant',
+        content: null,
+        tool_calls: [
+          {
+            id: 'call_1',
+            type: 'function',
+            function: { name: 'getNeighbours', arguments: '{"regionKeys":["a"]}' },
+          },
+        ],
+      },
+      { role: 'tool', tool_call_id: 'call_1', content: JSON.stringify({ neighbours: ['b'] }) },
+    ]);
+    // the executor received the parsed (object) arguments, not the raw string
+    expect(executorCalls).toEqual([{ name: 'getNeighbours', args: { regionKeys: ['a'] } }]);
+  });
+
+  it('a content-only response ends in one round (the executor is never called)', async () => {
+    const sent: string[] = [];
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      return contentResponse('done');
+    };
+    const llm = createLlmClient({ transport, apiBase: 'http://x/v1', model: 'm' });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      () => {
+        throw new Error('the executor must not be called');
+      },
+    );
+    expect(out).toBe('done');
+    expect(sent).toHaveLength(1);
+  });
+
+  it('bounds the tool rounds: maxRounds tool-call rounds, then one final no-tools request', async () => {
+    const sent: string[] = [];
+    let n = 0;
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      n += 1;
+      if (n <= 2) return toolCallResponse(`call_${n}`, 'getNeighbours', '{}');
+      return contentResponse('committed');
+    };
+    const llm = createLlmClient({ transport, apiBase: 'http://x/v1', model: 'm' });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      () => JSON.stringify({ neighbours: [] }),
+      { maxRounds: 2 },
+    );
+    expect(out).toBe('committed');
+    expect(sent).toHaveLength(3); // 2 tool rounds + the forced final request
+    expect(JSON.parse(sent[2]).tools).toBeUndefined(); // the final request has no tools
+  });
+
+  it('malformed tool arguments produce an "invalid tool arguments" tool message (no throw)', async () => {
+    const sent: string[] = [];
+    let n = 0;
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      n += 1;
+      if (n === 1) return toolCallResponse('call_1', 'getNeighbours', '{not valid json');
+      return contentResponse('recovered');
+    };
+    const llm = createLlmClient({ transport, apiBase: 'http://x/v1', model: 'm' });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      () => {
+        throw new Error('the executor must not be called on malformed args');
+      },
+    );
+    expect(out).toBe('recovered');
+    const body2 = JSON.parse(sent[1]);
+    const toolMsg = body2.messages.find((m: { role?: string }) => m.role === 'tool');
+    expect(toolMsg).toBeDefined();
+    expect(toolMsg.content).toMatch(/invalid tool arguments/);
+  });
+
+  it('retries a tool-call round on transient failure and still resolves the tool (500 → tool_calls → content)', async () => {
+    const sent: string[] = [];
+    let n = 0;
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      n += 1;
+      if (n === 1) return httpError(500);
+      if (n === 2) return toolCallResponse('call_1', 'getNeighbours', '{"regionKeys":["a"]}');
+      return contentResponse('ok');
+    };
+    const llm = createLlmClient({
+      transport,
+      apiBase: 'http://x/v1',
+      model: 'm',
+      retryBaseDelayMs: 1,
+    });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      () => JSON.stringify({ neighbours: [] }),
+    );
+    expect(out).toBe('ok');
+    expect(sent).toHaveLength(3);
+  });
+
+  it('a tool-call response is never treated as a truncation failure (content null is fine)', async () => {
+    const sent: string[] = [];
+    const transport = async (_url: string, init?: RequestInit) => {
+      sent.push(String(init?.body ?? ''));
+      if (sent.length === 1) return toolCallResponse('call_1', 'getNeighbours', '{}');
+      return contentResponse('ok');
+    };
+    const llm = createLlmClient({ transport, apiBase: 'http://x/v1', model: 'm' });
+    const out = await llm.chatWithTools!(
+      [{ role: 'user', content: 'hi' }],
+      [tool],
+      () => JSON.stringify({ neighbours: [] }),
+    );
+    expect(out).toBe('ok');
+    expect(sent).toHaveLength(2); // no retry of the first (successful) round
+  });
+});

server/llm.ts

@@ -23,12 +23,55 @@
 // to 3 total attempts and 2s→3s backoff (±20% jitter). HTTP 4xx is a
 // deterministic client error and throws immediately, with no retry. Every
 // call is logged: one line on success, one on final failure.
+//
+// Function calling: `chatWithTools()` extends `chat()` with the OpenAI tool
+// loop. When the model answers with `finish_reason: "tool_calls"`, the client
+// runs the provided executor for every requested call, appends the assistant
+// tool-call message plus one `tool` result message per call, and re-sends the
+// growing history until the model produces a final `content`. The loop is
+// bounded to DEFAULT_MAX_TOOL_ROUNDS (6) tool rounds; if the budget is spent
+// without a final answer, one last *no-tools* request forces the model to
+// commit. The same retry/backoff/reasoning-effort machinery applies per
+// request, so an injectable transport only has to forward `tools` in the body
+// and accept `assistant`/`tool` messages in the history. The deterministic
+// stub answers plain `content` (no tool calls) and therefore bypasses the
+// loop in a single round.
 
 export interface ChatMessage {
   role: 'system' | 'user' | 'assistant';
   content: string;
 }
 
+/** One OpenAI-style function call the model requests (`finish_reason: "tool_calls"`). */
+export interface ToolCallSpec {
+  id: string;
+  type: 'function';
+  function: { name: string; arguments: string };
+}
+
+/** A function the model may call (one OpenAI `tools` entry). */
+export interface ToolDefinition {
+  type: 'function';
+  function: {
+    name: string;
+    description?: string;
+    parameters?: Record<string, unknown>;
+  };
+}
+
+/**
+ * The full message vocabulary a request can carry: plain chat messages, plus
+ * assistant messages that request tool calls and the `tool` results that
+ * answer them (the OpenAI function-calling wire shape).
+ */
+export type WireMessage =
+  | ChatMessage
+  | { role: 'assistant'; content: string | null; tool_calls: ToolCallSpec[] }
+  | { role: 'tool'; tool_call_id: string; content: string };
+
+/** Executes one tool call; the returned string is fed back to the model as the `tool` result. */
+export type ToolExecutor = (name: string, args: Record<string, unknown>) => string;
+
 /** A network call. The default implementation is native fetch. */
 export type Transport = (url: string, init?: RequestInit) => Promise<Response>;
 
@@ -39,6 +82,18 @@ export interface ChatOptions {
 
 export interface LlmClient {
   chat(messages: ChatMessage[], opts?: ChatOptions): Promise<string>;
+  /**
+   * The function-calling variant of chat() — see the file header for the loop
+   * semantics (bounded tool rounds, then a forced final answer). Optional on
+   * the interface: minimal test doubles may omit it, and callers (the
+   * engine's runTurn) fall back to chat() when it is absent.
+   */
+  chatWithTools?(
+    messages: WireMessage[],
+    tools: ToolDefinition[],
+    executeTool: ToolExecutor,
+    opts?: ChatOptions & { maxRounds?: number },
+  ): Promise<string>;
   listModels(): Promise<string[]>;
 }
 
@@ -63,9 +118,17 @@ export const DEFAULT_MAX_TOKENS = 4000;
  */
 export const DEFAULT_REASONING_EFFORT = 'low';
 
-/** Total attempts `chat()` makes before giving up (1 initial + 2 retries). */
+/** Total attempts per request (chat / chatWithTools) before giving up (1 initial + 2 retries). */
 export const MAX_ATTEMPTS = 3;
 
+/**
+ * Max tool-call rounds (assistant tool_calls → tool results) a chatWithTools
+ * loop may make before a final no-tools request forces the answer. Keeps a
+ * turn bounded even if the model keeps asking for data; a realistic turn uses
+ * 0–2 rounds.
+ */
+export const DEFAULT_MAX_TOOL_ROUNDS = 6;
+
 /** Base retry backoff: retry 1 waits 2000ms, retry 2 waits 3000ms, each ±20% jitter. */
 const RETRY_BASE_DELAY_MS = 2000;
 
@@ -154,6 +217,30 @@ function isNetworkError(err: unknown): boolean {
   );
 }
 
+/** Parse the wire `tool_calls` array into validated ToolCallSpecs (malformed entries are dropped). */
+function parseToolCalls(raw: unknown): ToolCallSpec[] {
+  if (!Array.isArray(raw)) return [];
+  const out: ToolCallSpec[] = [];
+  for (const tc of raw) {
+    if (!tc || typeof tc !== 'object') continue;
+    const t = tc as Record<string, unknown>;
+    const fn = t.function as Record<string, unknown> | undefined;
+    if (!fn || typeof fn.name !== 'string' || fn.name === '') continue;
+    const argumentsText =
+      typeof fn.arguments === 'string'
+        ? fn.arguments
+        : fn.arguments != null
+          ? JSON.stringify(fn.arguments)
+          : '{}';
+    out.push({
+      id: typeof t.id === 'string' && t.id !== '' ? t.id : `call_${out.length}`,
+      type: 'function',
+      function: { name: fn.name, arguments: argumentsText },
+    });
+  }
+  return out;
+}
+
 /** One transport attempt, classified as success / retryable / fatal. */
 interface Attempt {
   status?: number;
@@ -161,6 +248,7 @@ interface Attempt {
   retryable: boolean;
   content?: string;
   finishReason?: string | null;
+  toolCalls?: ToolCallSpec[];
 }
 
 export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
@@ -179,7 +267,7 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
 
   /**
    * One POST to /chat/completions. Classifies the outcome:
-   *   - success   → content + finish_reason
+   *   - success   → content and/or tool_calls
    *   - retryable → timeout/abort, HTTP 5xx, network error, null/empty content
    *   - fatal     → HTTP 4xx (deterministic client error) or an unexpected throw
    */
@@ -213,12 +301,27 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
     const body = (await res.json()) as {
       choices?: {
         finish_reason?: string | null;
-        message?: { content?: string; reasoning?: string | null };
+        message?: { content?: string; reasoning?: string | null; tool_calls?: unknown };
       }[];
     };
+    const choice = body.choices?.[0];
+    const message = choice?.message;
+    // A tool-call round is a SUCCESS even though `content` is null there: the
+    // model is asking for data, not failing (never treat it as truncation).
+    const toolCalls = parseToolCalls(message?.tool_calls);
+    if (toolCalls.length > 0) {
+      return {
+        status: res.status,
+        retryable: false,
+        content:
+          typeof message?.content === 'string' && message.content !== '' ? message.content : undefined,
+        finishReason: choice?.finish_reason ?? null,
+        toolCalls,
+      };
+    }
     // The reasoning model can exhaust its output budget on the CoT and return
     // a null `content` — treat that as a retryable truncation, not a success.
-    const content = body.choices?.[0]?.message?.content;
+    const content = message?.content;
     if (typeof content !== 'string' || content === '') {
       return {
         status: res.status,
@@ -230,11 +333,16 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
       status: res.status,
       retryable: false,
       content,
-      finishReason: body.choices?.[0]?.finish_reason ?? null,
+      finishReason: choice?.finish_reason ?? null,
     };
   }
 
-  async function chat(messages: ChatMessage[], opts: ChatOptions = {}): Promise<string> {
+  /** Build one /chat/completions request body. `tools` is only included when non-empty, so plain chat() keeps its exact legacy shape. */
+  function buildPayload(
+    messages: WireMessage[],
+    tools: ToolDefinition[] | undefined,
+    opts: ChatOptions,
+  ): Record<string, unknown> {
     const payload: Record<string, unknown> = {
       model,
       messages,
@@ -245,7 +353,16 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
     };
     if (opts.temperature != null) payload.temperature = opts.temperature;
     if (sendEffort) payload.reasoning_effort = effort;
+    if (tools && tools.length > 0) payload.tools = tools;
+    return payload;
+  }
 
+  /**
+   * One request with the standard retry/backoff: up to MAX_ATTEMPTS per
+   * request; resolves with a successful Attempt (content and/or toolCalls) or
+   * throws the last error once the attempts are spent.
+   */
+  async function requestWithRetry(payload: Record<string, unknown>): Promise<Attempt> {
     const totalStart = Date.now();
     let lastStatus: number | undefined;
     let lastError: Error = new Error('chat failed: no attempt completed');
@@ -255,12 +372,13 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
       if (out.status !== undefined) lastStatus = out.status;
       if (out.error) lastError = out.error;
 
-      if (out.content !== undefined) {
+      if (out.content !== undefined || out.toolCalls !== undefined) {
         console.log('[llm] chat ok', {
           ms: Date.now() - totalStart,
           finishReason: out.finishReason ?? null,
+          toolCalls: out.toolCalls?.length ?? 0,
         });
-        return out.content;
+        return out;
       }
       // Give up on a non-retryable failure, or when the last attempt is spent.
       if (!out.retryable || attempt === MAX_ATTEMPTS) {
@@ -278,6 +396,68 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
     throw lastError;
   }
 
+  async function chat(messages: ChatMessage[], opts: ChatOptions = {}): Promise<string> {
+    const out = await requestWithRetry(buildPayload(messages, undefined, opts));
+    return out.content ?? '';
+  }
+
+  /**
+   * The function-calling loop — see the file header. Bounded: at most
+   * `maxRounds` tool rounds, then one final no-tools request forces an answer.
+   * Throws like chat() only on transport-level exhaustion (the engine maps that
+   * to a 502; bad *content* never throws, it is parsed defensively downstream).
+   */
+  async function chatWithTools(
+    initial: WireMessage[],
+    tools: ToolDefinition[],
+    executeTool: ToolExecutor,
+    opts: ChatOptions & { maxRounds?: number } = {},
+  ): Promise<string> {
+    const maxRounds = Math.max(1, opts.maxRounds ?? DEFAULT_MAX_TOOL_ROUNDS);
+    const messages: WireMessage[] = [...initial];
+    for (let round = 0; round < maxRounds; round++) {
+      const out = await requestWithRetry(buildPayload(messages, tools, opts));
+      // Tool calls win over any partial content: the model asked for data
+      // before it finished.
+      if (out.toolCalls && out.toolCalls.length > 0) {
+        messages.push({
+          role: 'assistant',
+          content: out.content ?? null,
+          tool_calls: out.toolCalls,
+        });
+        for (const tc of out.toolCalls) {
+          let result: string;
+          try {
+            const parsed: unknown =
+              tc.function.arguments !== '' ? JSON.parse(tc.function.arguments) : {};
+            const args =
+              parsed !== null && typeof parsed === 'object' && !Array.isArray(parsed)
+                ? (parsed as Record<string, unknown>)
+                : {};
+            result = executeTool(tc.function.name, args);
+          } catch (err) {
+            // Malformed arguments are not fatal: hand the model an error
+            // result so it can re-call with valid arguments or move on.
+            result = JSON.stringify({
+              error: `invalid tool arguments: ${err instanceof Error ? err.message : String(err)}`,
+            });
+          }
+          messages.push({ role: 'tool', tool_call_id: tc.id, content: result });
+        }
+        continue;
+      }
+      if (out.content !== undefined) return out.content;
+    }
+    // The tool budget is spent without a final answer: one last no-tools
+    // request forces the model to commit.
+    messages.push({
+      role: 'user',
+      content: 'You have reached your tool budget. Answer now with the final result only.',
+    });
+    const out = await requestWithRetry(buildPayload(messages, undefined, opts));
+    return out.content ?? '';
+  }
+
   async function listModels(): Promise<string[]> {
     const res = await transport(`${apiBase}/models`, {
       signal: AbortSignal.timeout(timeoutMs),
@@ -287,5 +467,5 @@ export function createLlmClient(deps: LlmClientDeps = {}): LlmClient {
     return (body.data ?? []).map((m) => m.id);
   }
 
-  return { chat, listModels };
+  return { chat, chatWithTools, listModels };
 }

server/map.test.ts

@@ -1,6 +1,18 @@
 import { describe, expect, it } from 'vitest';
 import { buildRegionMap } from './map';
-import { mapFeatureOwner, nationColor, regionOwner, type RegionMap } from '../shared/protocol';
+import {
+  mapFeatureOwner,
+  nationColor,
+  NO_MANS_LAND_FILL,
+  NO_MANS_LAND_STROKE,
+  OWNED_STROKE,
+  regionFillStyle,
+  regionOwner,
+  UNOWNED_FILL,
+  UNOWNED_STROKE,
+  unownedTooltipLabel,
+  type RegionMap,
+} from '../shared/protocol';
 import type { GameState } from '../shared/types';
 
 // Region-key fixtures (v0.19, #16 P1): ownership and the RegionMap are now keyed
@@ -35,6 +47,9 @@ const state: GameState = {
   events: [],
   pending: [],
   version: 1,
+  unowned: [],
+  pendingNationOps: [],
+  markers: [],
 };
 
 // The RegionMap built from the fixture: the authoritative region key → owner source.
@@ -49,6 +64,16 @@ describe('buildRegionMap', () => {
     // a region nobody owns is simply absent
     expect(m['normandie-dddd']).toBeUndefined();
   });
+
+  it('(v0.22 #16 P3) a released (no-man\'s-land) key — in GameState.unowned, owned by no nation — is absent: absence IS unowned', () => {
+    const s: GameState = JSON.parse(JSON.stringify(state));
+    // simulate a mid-game release: the key left every territory and entered unowned
+    s.nations.uk.territory = s.nations.uk.territory.filter((k) => k !== 'albania-aaaa');
+    s.unowned = ['albania-aaaa'];
+    const m = buildRegionMap(s);
+    expect(m['albania-aaaa']).toBeUndefined(); // the map cannot tell which kind of unowned
+    expect(s.unowned).toEqual(['albania-aaaa']); // ...the client's GameState.unowned decides that
+  });
 });
 
 describe('regionOwner', () => {
@@ -143,3 +168,48 @@ describe('nationColor', () => {
     expect(nationColor('uk')).toMatch(/^hsl\(\d+ 58% 46%\)$/);
   });
 });
+
+// (v0.22, #16 P3) The no-man's-land presentation contract lives in
+// shared/protocol (shared/*.test.ts is not in the vitest glob, so these
+// tests live here): the distinct visible grey, the faint preset-unassigned
+// look, the per-kind borders, and the tooltip sub-line.
+describe('no man\'s land presentation contract (v0.22 #16 P3)', () => {
+  it('regionFillStyle: an owned region uses its nation color + the owned border', () => {
+    expect(regionFillStyle(regions['albania-aaaa'], false)).toEqual({
+      fill: nationColor('uk'),
+      stroke: OWNED_STROKE,
+    });
+    expect(regionFillStyle(regions['brandenburg-cccc'], true)).toEqual({
+      fill: nationColor('de'),
+      stroke: OWNED_STROKE,
+    }); // the no-man's-land flag never affects an owned region
+  });
+
+  it('regionFillStyle: an unowned region that IS no man\'s land gets the distinct visible grey', () => {
+    expect(regionFillStyle(undefined, true)).toEqual({
+      fill: NO_MANS_LAND_FILL,
+      stroke: NO_MANS_LAND_STROKE,
+    });
+  });
+
+  it('regionFillStyle: an unowned region that was never released keeps the faint look', () => {
+    expect(regionFillStyle(undefined, false)).toEqual({
+      fill: UNOWNED_FILL,
+      stroke: UNOWNED_STROKE,
+    });
+  });
+
+  it('the no-man\'s-land grey can never collide with a nation color (hue-less vs HSL)', () => {
+    expect(NO_MANS_LAND_FILL).not.toMatch(/^hsl\(/);
+    expect(NO_MANS_LAND_FILL).not.toBe(nationColor('uk'));
+    expect(NO_MANS_LAND_FILL).not.toBe(nationColor('de'));
+    // and it must be visibly different from the faint preset-unassigned fill
+    expect(NO_MANS_LAND_FILL).not.toBe(UNOWNED_FILL);
+    expect(NO_MANS_LAND_STROKE).not.toBe(UNOWNED_STROKE);
+  });
+
+  it('unownedTooltipLabel: the tooltip sub-line names the two kinds of unowned', () => {
+    expect(unownedTooltipLabel(true)).toBe("No man's land");
+    expect(unownedTooltipLabel(false)).toBe('No owner');
+  });
+});

server/map.ts

@@ -3,6 +3,13 @@
 // color (see shared.nationColor). The client merges this onto the sub-national
 // regions.geo.json (resolving each feature by its own region key) and calls
 // source.setData(). Format-agnostic: it maps whatever keys sit in territory.
+//
+// A key ABSENT from the returned map is unowned (no nation's territory holds
+// it) — this covers both regions a preset never assigned and regions released
+// to no man's land mid-game (v0.22, #16 P3). The map deliberately does NOT
+// distinguish the two: the visible no-man's-land grey vs the faint
+// preset-unassigned look is decided by the client from `GameState.unowned`
+// (see shared/protocol.ts's regionFillStyle).
 import { nationColor, type RegionMap } from '../shared/protocol';
 import type { GameState } from '../shared/types';
 

server/regions.test.ts

@@ -5,9 +5,13 @@ import { tmpdir } from 'node:os';
 import path from 'node:path';
 import {
   allTerritoryKeys,
+  centroidOf,
   expandCountriesToKeys,
+  hasAdjacency,
+  hasCentroids,
   hasRegionData,
   loadRegions,
+  neighboursOf,
   referenceForKeys,
   regionName,
   resetRegions,
@@ -25,9 +29,9 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
     expect(loadRegions(root)).toBe(true);
   });
 
-  it('loads the full manifest: 1,796 unique valid region keys', () => {
+  it('loads the full manifest: 1,800 unique valid region keys', () => {
     expect(hasRegionData()).toBe(true);
-    expect(validKeys().size).toBe(1796);
+    expect(validKeys().size).toBe(1800);
   });
 
   it('expands an ISO_A3 country to the region keys of all its sub-regions', () => {
@@ -49,6 +53,21 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
     expect(ref['aisne-gstu']).toBe('Aisne (FRA)');
   });
 
+  it('expands RUS to all 84 sub-regions after the #31 + #41 Arkhangel splits (no ownership gap at game init)', () => {
+    // #31 split RU-ARK into the mainland + New Earth + Severnaya Zemlya; #41
+    // repartitioned the mainland into the core (unchanged key) + Pechora +
+    // Yamal. A fresh game's RUS territory (expanded from the preset's
+    // country list) must contain all five sub-region keys — the main one
+    // (ownership-safe, unchanged key) plus the island and band ones.
+    const rus = expandCountriesToKeys(['RUS']);
+    expect(rus).toHaveLength(84);
+    expect(rus).toContain('arkhangel-sk-lhbk');
+    expect(rus).toContain('new-earth-eikt');
+    expect(rus).toContain('severnaya-zemlya-awqp');
+    expect(rus).toContain('pechora-qwhs');
+    expect(rus).toContain('yamal-gosw');
+  });
+
   it('referenceForKeys labels only known keys and omits unknown ones', () => {
     const ref = referenceForKeys(['ain-lqtt', 'not-a-real-key-xyz']);
     expect(ref['ain-lqtt']).toBe('Ain (FRA)');
@@ -84,11 +103,52 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
       events: [],
       pending: [],
       version: 1,
+      unowned: [],
+      pendingNationOps: [],
+      markers: [],
     };
     // 16 GBR sub-regions + 42 FRA sub-regions, no overlap between the two.
     expect(allTerritoryKeys(state).size).toBe(58);
   });
 
+  it('hasAdjacency() is true: the region-adjacency manifest loaded (v0.21 #16 P2)', () => {
+    expect(hasAdjacency()).toBe(true);
+  });
+
+  it('neighboursOf returns the union of bordering keys (deduped, sorted, queried excluded)', () => {
+    // known mutual pairs from the manifest (verified in the Stage 1 spot checks)
+    const moselle = neighboursOf(['moselle-rygy']);
+    expect(moselle).toContain('baden-wurttemberg-oyje'); // FRA/DEU border
+    expect(neighboursOf(['baden-wurttemberg-oyje'])).toContain('moselle-rygy'); // mutual
+    expect(neighboursOf(['acre-ekzw'])).toContain('loreto-ipkx'); // BRA/PER border
+    expect(neighboursOf(['loreto-ipkx'])).toContain('acre-ekzw'); // mutual
+
+    // union + dedupe + sorted + the queried keys themselves excluded
+    const union = neighboursOf(['moselle-rygy', 'baden-wurttemberg-oyje']);
+    expect(union).toEqual([...union].sort());
+    expect(new Set(union).size).toBe(union.length); // no duplicates
+    expect(union).not.toContain('moselle-rygy');
+    expect(union).not.toContain('baden-wurttemberg-oyje');
+  });
+
+  it('neighboursOf returns [] for unknown keys or an empty set', () => {
+    expect(neighboursOf(['not-a-real-key-xyz'])).toEqual([]);
+    expect(neighboursOf([])).toEqual([]);
+  });
+
+  it('(v0.27 #44) hasCentroids() is true and centroidOf resolves a real key to a plausible location', () => {
+    expect(hasCentroids()).toBe(true);
+    const ain = centroidOf('ain-lqtt');
+    expect(ain).toBeDefined();
+    expect(ain!.lat).toBeCloseTo(46.16, 1);
+    expect(ain!.lon).toBeCloseTo(4.8, 1);
+    expect(ain!.spread).toBeGreaterThan(0);
+  });
+
+  it('(v0.27 #44) centroidOf returns undefined for an unknown key', () => {
+    expect(centroidOf('not-a-real-key-xyz')).toBeUndefined();
+  });
+
   describe('graceful degradation with no region data', () => {
     beforeEach(() => resetRegions());
 
@@ -99,6 +159,12 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
       expect(referenceForKeys(['FRA'])).toEqual({});
       expect(validKeys().size).toBe(0);
       expect(regionName('FRA')).toBeUndefined();
+      // and no adjacency: the LLM tool / frontier field switch off
+      expect(hasAdjacency()).toBe(false);
+      expect(neighboursOf(['moselle-rygy'])).toEqual([]);
+      // and no centroids: the marker-placement path degrades to a no-op
+      expect(hasCentroids()).toBe(false);
+      expect(centroidOf('ain-lqtt')).toBeUndefined();
     });
   });
 
@@ -134,13 +200,37 @@ describe('loadRegions resolves the manifest per environment (dev public/ vs prod
   it('loads from dist/ when public/ is absent (the prod container layout)', () => {
     expect(loadRegions(prodRoot)).toBe(true);
     expect(hasRegionData()).toBe(true);
-    expect(validKeys().size).toBe(1796);
+    expect(validKeys().size).toBe(1800);
     expect(expandCountriesToKeys(['FRA'])).toHaveLength(42);
   });
 
   it('still loads from public/ (the dev layout, the first candidate)', () => {
     expect(loadRegions(realRoot)).toBe(true);
-    expect(validKeys().size).toBe(1796);
+    expect(validKeys().size).toBe(1800);
+  });
+
+  it('a dist/ WITHOUT the adjacency manifest degrades: hasAdjacency() false, neighboursOf []', () => {
+    // this fixture copies only region-keys.json + regions.geo.json (no
+    // region-adjacency.json) — the server must boot and serve turns with the
+    // tool/frontier simply switched off.
+    expect(loadRegions(prodRoot)).toBe(true);
+    expect(hasAdjacency()).toBe(false);
+    expect(neighboursOf(['moselle-rygy'])).toEqual([]);
+    // and no centroids (not copied into this dist/) -> marker placement degrades
+    expect(hasCentroids()).toBe(false);
+    expect(centroidOf('ain-lqtt')).toBeUndefined();
+  });
+
+  it('(v0.27 #44) a dist/ WITH the centroids manifest loads them (prod layout)', () => {
+    copyFileSync(
+      path.join(realRoot, 'public', 'region-centroids.json'),
+      path.join(prodRoot, 'dist', 'region-centroids.json'),
+    );
+    expect(loadRegions(prodRoot)).toBe(true);
+    expect(hasCentroids()).toBe(true);
+    const ain = centroidOf('ain-lqtt');
+    expect(ain).toBeDefined();
+    expect(ain!.lat).toBeCloseTo(46.16, 1);
   });
 
   it('returns false and no data when neither public/ nor dist/ holds the files', () => {

server/regions.ts

@@ -1,18 +1,27 @@
 // Region-key data access (server). Loads the deterministic region-key manifest
-// (region-keys.json: stable feature id -> region key) and the sub-national geo
-// (regions.geo.json: feature id -> { name, parent }) — from public/ in dev (Vite
-// serves it) or dist/ in prod (Vite copies public/* -> dist/ at build, and the
-// Docker image keeps only dist/) — and joins them into the lookups the
-// region-level ownership model (v0.19, #16 P1) needs:
+// (region-keys.json: stable feature id -> region key), the sub-national geo
+// (regions.geo.json: feature id -> { name, parent }), and — optionally — the
+// precomputed region-adjacency manifest (region-adjacency.json: region key ->
+// bordering region keys, built by scripts/build-region-adjacency.mjs) and the
+// precomputed region-centroid manifest (region-centroids.json: region key ->
+// { lat, lon, spread }, built by scripts/build-region-centroids.mjs) — all
+// from public/ in dev (Vite serves it) or dist/ in prod (Vite copies
+// public/* -> dist/ at build, and the Docker image keeps only dist/) — and
+// joins them into the lookups the region-level ownership model needs:
 //
-//   - expand a nation's ISO_A3 country list -> the region keys of all its sub-regions
+//   - expand a nation's ISO_A3 country list -> the region keys of all its sub-regions (v0.19, #16 P1)
 //   - build the LLM "regions" reference table (key -> "name (parent ISO_A3)")
 //   - the set of all valid region keys (to ignore hallucinated keys in applyTurnResult)
+//   - neighboursOf(): the union of the bordering keys for a set of keys — the
+//     data behind the LLM's getNeighbours tool and the player-frontier prompt
+//     field (v0.21, #16 P2)
+//   - centroidOf(): a region key's precomputed anchor point ({ lat, lon, spread })
+//     — the data behind LLM-placed map markers (v0.27, #44)
 //
-// Deliberately turf-free: it reads the two JSON files with plain JSON.parse and
-// never imports @turf/@types/geojson (importing one pulls @types/geojson into the
-// tsc program and breaks WorldMap.tsx; see the v0.17 changelog note). Loaded once
-// at boot; the accessors below are pure data reads thereafter.
+// Deliberately turf-free: it reads the JSON files with plain JSON.parse and
+// never imports @turf/@types/geojson (importing one pulls @types/geojson into
+// the tsc program and breaks WorldMap.tsx; see the v0.17 changelog note).
+// Loaded once at boot; the accessors below are pure data reads thereafter.
 import { existsSync, readFileSync } from 'node:fs';
 import path from 'node:path';
 import type { GameState } from '../shared/types';
@@ -32,23 +41,37 @@ interface RegionData {
   keysByCountry: Record<string, string[]>;
   /** the set of all region keys. */
   validKeys: Set<string>;
+  /** region key -> bordering region keys (from public/region-adjacency.json). */
+  adjacency: Record<string, string[]>;
+  /** region key -> anchor point (from public/region-centroids.json). */
+  centroids: Record<string, { lat: number; lon: number; spread: number }>;
 }
 
 let data: RegionData | null = null;
 
 /**
- * Load (or reload) the region-key manifest + geo. Idempotent. The two files are
- * served to the client from `public/` in dev (Vite serves it directly) and from
- * `dist/` in prod (Vite copies `public/*` → `dist/` at build and the Docker image
- * keeps only `dist/`), so probe `public/` then `dist/` (plus the root as a last
- * resort) and use the first directory that holds both files. Returns true when
- * both loaded cleanly; a missing/broken pair clears the data and returns false
- * so the server still boots and degrades gracefully (expansion becomes a no-op,
+ * Load (or reload) the region-key manifest, geo, adjacency, and centroids.
+ * Idempotent.
+ * The files are served to the client from `public/` in dev (Vite serves it
+ * directly) and from `dist/` in prod (Vite copies `public/*` → `dist/` at build
+ * and the Docker image keeps only `dist/`), so probe `public/` then `dist/`
+ * (plus the root as a last resort) and use the first directory that holds the
+ * key manifest + geo. The adjacency manifest is OPTIONAL: when it is missing
+ * or broken, `adjacency` stays empty and `neighboursOf`/`hasAdjacency` simply
+ * report "no adjacency" (the LLM tool and the frontier prompt field switch
+ * off; everything else keeps working). The centroid manifest is likewise
+ * OPTIONAL (v0.27, #44): when missing or broken, `centroids` stays empty and
+ * `centroidOf`/`hasCentroids` report "no centroids" (new map markers can't be
+ * placed, but everything else keeps working). Returns true when the core pair loaded
+ * cleanly; a missing/broken pair clears the data and returns false so the
+ * server still boots and degrades gracefully (expansion becomes a no-op,
  * ownership falls back to the raw input keys).
  */
 export function loadRegions(root: string): boolean {
   const keyFile = 'region-keys.json';
   const geoFile = 'regions.geo.json';
+  const adjacencyFile = 'region-adjacency.json';
+  const centroidsFile = 'region-centroids.json';
   const base = [
     path.join(root, 'public'), // dev: Vite serves public/ at /
     path.join(root, 'dist'), // prod: Vite copies public/* -> dist/ (== clientDir)
@@ -78,7 +101,53 @@ export function loadRegions(root: string): boolean {
       validKeys.add(key);
       if (parent) (keysByCountry[parent] ??= []).push(key);
     }
-    data = { idToKey, keyToInfo, keysByCountry, validKeys };
+
+    // Adjacency is optional: a missing file means "no adjacency data".
+    let adjacency: Record<string, string[]> = {};
+    const adjacencyPath = path.join(base, adjacencyFile);
+    if (existsSync(adjacencyPath)) {
+      try {
+        adjacency = JSON.parse(readFileSync(adjacencyPath, 'utf8')) as Record<string, string[]>;
+      } catch (err) {
+        // A corrupt manifest must not kill the core region data: degrade to
+        // "no adjacency" (the LLM tool / frontier guidance simply switch off).
+        console.error('[regions] failed to load region-adjacency.json, continuing without it', err);
+        adjacency = {};
+      }
+    }
+
+    // Centroids are optional too (v0.27, #44): a missing/broken file means
+    // "no centroid data" — new markers can't be placed (their adds are
+    // dropped), but everything else keeps working.
+    let centroids: Record<string, { lat: number; lon: number; spread: number }> = {};
+    const centroidsPath = path.join(base, centroidsFile);
+    if (existsSync(centroidsPath)) {
+      try {
+        const raw = JSON.parse(readFileSync(centroidsPath, 'utf8')) as Record<
+          string,
+          { lat?: unknown; lon?: unknown; spread?: unknown }
+        >;
+        // Keep only well-formed entries; a corrupt file degrades to "none".
+        for (const [k, v] of Object.entries(raw)) {
+          if (
+            v &&
+            typeof v.lat === 'number' &&
+            typeof v.lon === 'number' &&
+            typeof v.spread === 'number' &&
+            Number.isFinite(v.lat) &&
+            Number.isFinite(v.lon) &&
+            Number.isFinite(v.spread)
+          ) {
+            centroids[k] = { lat: v.lat, lon: v.lon, spread: v.spread };
+          }
+        }
+      } catch (err) {
+        console.error('[regions] failed to load region-centroids.json, continuing without it', err);
+        centroids = {};
+      }
+    }
+
+    data = { idToKey, keyToInfo, keysByCountry, validKeys, adjacency, centroids };
     return validKeys.size > 0;
   } catch (err) {
     console.error('[regions] failed to load region data', err);
@@ -151,3 +220,51 @@ export function allTerritoryKeys(state: GameState): Set<string> {
 export function validKeys(): ReadonlySet<string> {
   return data ? data.validKeys : new Set<string>();
 }
+
+/**
+ * True when the region-adjacency manifest loaded with at least one entry.
+ * Callers (the server's jump route) use this to decide whether to hand the
+ * engine an adjacency resolver (which turns on the LLM's getNeighbours tool
+ * and the frontier prompt field) or fall back to the plain chat() path.
+ */
+export function hasAdjacency(): boolean {
+  return data !== null && Object.keys(data.adjacency).length > 0;
+}
+
+/**
+ * True when the region-centroid manifest loaded with at least one entry
+ * (v0.27, #44). The server's jump route uses this to decide whether to hand
+ * the engine a centroid resolver (which lets a turn place new map markers)
+ * or skip marker placement (existing markers are still maintained).
+ */
+export function hasCentroids(): boolean {
+  return data !== null && Object.keys(data.centroids).length > 0;
+}
+
+/**
+ * The precomputed anchor point for a region key: the centroid of its
+ * largest-area part, plus a `spread` (≈ 0.1 × that part's smallest bbox
+ * dimension, in degrees) the engine scatters markers within
+ * ±(spread/2) of the centroid. `undefined` for an unknown key or when no
+ * centroid data is loaded (v0.27, #44).
+ */
+export function centroidOf(key: string): { lat: number; lon: number; spread: number } | undefined {
+  return data?.centroids[key];
+}
+
+/**
+ * The union of the region keys that share a land border with any of the given
+ * keys — deduplicated, the queried keys themselves excluded, and sorted for
+ * determinism. This is the data behind the LLM's getNeighbours tool and the
+ * player-frontier computation in the turn prompt (v0.21, #16 P2). Returns
+ * `[]` when no region data (or no adjacency manifest) is loaded.
+ */
+export function neighboursOf(keys: Iterable<string>): string[] {
+  if (!data) return [];
+  const out = new Set<string>();
+  for (const key of keys) {
+    for (const n of data.adjacency[key] ?? []) out.add(n);
+  }
+  for (const key of keys) out.delete(key); // never report a key as its own neighbour
+  return [...out].sort();
+}

server/stub.ts

@@ -2,7 +2,7 @@
 // sets LLM_STUB=1) so the whole loop is reproducible with no live model. It
 // speaks the OpenAI chat-completions wire shape, so it plugs in as a Transport.
 import { createLlmClient, type ChatMessage, type Transport } from './llm';
-import { addDays, clampStat, type TurnEventSpec, type TurnResult } from '../shared/protocol';
+import { addDays, clampStat, type TerritoryChange, type TurnEventSpec, type TurnResult } from '../shared/protocol';
 import type { RoundItem } from '../shared/types';
 
 export const ADVISOR_MARKER = '<<ADVISOR>>';
@@ -13,10 +13,31 @@ export interface StubPayload {
     turn: number;
     date: string;
     playerNationId: string;
-    nations: Record<string, { stats: Record<string, number> }>;
+    nations: Record<string, { stats: Record<string, number>; territory?: string[] }>;
   };
   /** The raw pending round the engine emitted (one entry per queued item). */
   pending?: RoundItem[];
+  /**
+   * Region keys owned by other nations that share a land border with the
+   * player's territory — the engine's `frontier` field, computed from the
+   * adjacency manifest (v0.21, #16 P2). The stub cannot call tools, so it
+   * reads the frontier from the prompt instead.
+   */
+  frontier?: string[];
+  /**
+   * (v0.22, #16 P3) Region keys currently in no man's land (`state.unowned`),
+   * emitted by the engine's user prompt. The stub ignores this field — it
+   * never releases a region (see deterministicTurn), so no-man's-land behavior
+   * is covered by unit tests against applyTurnResult, not by the stub.
+   */
+  unowned?: string[];
+  /**
+   * (v0.27, #44) Current map markers (`{ id, type, name, regionKey, owner }`),
+   * emitted by the engine's user prompt. The stub ignores this field — it
+   * never places or removes a marker (see deterministicTurn), so the marker
+   * path is covered by unit tests against applyTurnResult, not by the stub.
+   */
+  markers?: Array<{ id: string; type: string; name: string; regionKey: string; owner: string | null }>;
 }
 
 function truncate(s: string, n: number): string {
@@ -31,6 +52,26 @@ function truncate(s: string, n: number): string {
  * caller can predict the exact next state for assertions. It always sets the
  * player's military to (current + 5) and allies the player with the first other
  * nation, advancing the date by 2 days.
+ *
+ * (v0.21, #16 P2) It also makes ONE contiguous conquest per turn: the player
+ * gains the first frontier region (sorted order) from its current owner, and
+ * that owner loses it. The stub bypasses the tool loop (it answers with plain
+ * content in one round), so the frontier comes from the prompt payload, not
+ * from a getNeighbours call. With an empty frontier (no controllable border)
+ * no territory change is emitted, keeping every existing assertion stable.
+ *
+ * (v0.22, #16 P3) The stub NEVER releases a region to no man's land (it
+ * always returns `unowned: []`) — e2e assertions rely on its fully-deterministic
+ * one-conquest behavior, so the release/re-claim path is exercised by unit
+ * tests only (see server/engine.test.ts).
+ *
+ * (v0.23, #16 P4a) The stub likewise NEVER proposes nation-management ops (it
+ * always returns `nationOps: []`) — the propose→confirm/reject flow is
+ * covered by unit tests only, keeping the e2e assertions untouched.
+ *
+ * (v0.27, #44) The stub likewise NEVER places or removes a map marker (it
+ * always returns `markers: { add: [], remove: [] }`) — the marker path is
+ * covered by unit tests only, keeping the e2e assertions untouched.
  */
 export function deterministicTurn(p: StubPayload): TurnResult {
   const state = p.state;
@@ -42,6 +83,23 @@ export function deterministicTurn(p: StubPayload): TurnResult {
     : 'us';
   const items = p.pending ?? [];
 
+  // The one deterministic region transfer: the player takes the first
+  // frontier region (sorted → stable) from whichever other nation owns it.
+  let territoryChanges: TerritoryChange[] = [];
+  const frontier = p.frontier ?? [];
+  if (state && frontier.length > 0) {
+    const key = frontier[0];
+    const loserId = Object.keys(state.nations).find(
+      (id) => id !== pid && (state.nations[id].territory ?? []).includes(key),
+    );
+    if (loserId) {
+      territoryChanges = [
+        { nation: pid, gain: [key], lose: [] },
+        { nation: loserId, gain: [], lose: [key] },
+      ];
+    }
+  }
+
   const events: TurnEventSpec[] =
     items.length === 0
       ? [
@@ -76,7 +134,10 @@ export function deterministicTurn(p: StubPayload): TurnResult {
     events,
     stateChanges: [{ nation: pid, stat: 'military', op: 'set', value: mil }],
     relations: otherId ? [{ a: pid, b: otherId, set: 'ally' }] : [],
-    territoryChanges: [],
+    territoryChanges,
+    unowned: [], // the stub never creates no man's land (see doc comment)
+    nationOps: [], // the stub never proposes nation ops (see doc comment)
+    markers: { add: [], remove: [] }, // the stub never touches markers (see doc comment)
   };
 }
 

shared/protocol.ts

@@ -6,10 +6,12 @@ import type {
   EventOutcome,
   EventType,
   GameState,
+  MarkerType,
   Nation,
   RelationStatus,
   StatKey,
 } from './types';
+import { MARKER_TYPES } from './types';
 
 /** A numeric change to one of a nation's 0–100 stats. */
 export type StateChange =
@@ -30,6 +32,81 @@ export interface TerritoryChange {
   lose: string[];
 }
 
+// --- Nation-management ops (v0.23 P4a / v0.24 P4b, #16: the hybrid "LLM
+// proposes, player confirms" model) ------------------------------------------
+//
+// Unlike stat / relation / territory deltas, a NationOp proposed in a turn is
+// NOT applied by that turn. It is stored as a *pending proposal* in
+// `GameState.pendingNationOps` and only takes effect when the player confirms
+// it (optionally editing it) or is dropped when the player rejects it. All
+// three kinds are implemented: rename (v0.23 P4a), split and merge (v0.24 P4b).
+
+/**
+ * The identity reference a nation is addressed by inside a {@link NationOp}.
+ * The LLM may use either the nation's stable `id` (the `nations` record key,
+ * e.g. `f`) or its human-readable `name` (e.g. `France`); the engine resolves
+ * it to a concrete `nationId` (id first, then a unique name match — see the
+ * engine's `resolveNationRef`).
+ */
+
+/**
+ * A **rename** proposal: change a nation's human-readable `name`. Only the
+ * `name` changes — the stable `id`, its territory keys, its relations (keyed
+ * by id), and the player pointer are all left untouched, so nothing downstream
+ * breaks. `to` is the new display name.
+ */
+export interface RenameOp {
+  kind: 'rename';
+  /** The target nation's id or current name (see the note above). */
+  nationRef: string;
+  /** The new display name to apply when the player confirms. */
+  to: string;
+}
+
+/**
+ * A **split** proposal (v0.24, #16 P4b). Describes the new nations a source
+ * nation is divided into. On confirm the source is dissolved: each part gets a
+ * fresh id, the region keys it was given (restricted to keys the source
+ * actually owns — first claim wins), fresh baseline stats, and a copy of the
+ * source's relations; any of the source's unclaimed keys go to `parts[0]`.
+ * When the source is the player's own nation the player chooses which part
+ * they lead (the confirm request's `edits.playerPart`, default `parts[0]`).
+ */
+export interface SplitOp {
+  kind: 'split';
+  /** The id/name of the nation being split. */
+  nationRef: string;
+  /** The new nations created from the split. */
+  parts: Array<{ name: string; territory?: string[] }>;
+}
+
+/**
+ * A **merge** proposal (v0.24, #16 P4b). Folds several nations into a single
+ * surviving nation. On confirm the survivor keeps its id (renamed to `into`,
+ * or to the confirm request's `edits.name`), its territory becomes the union
+ * of all inputs' territories, it keeps its own stats, and it inherits the
+ * union of all inputs' relations (its own winning per third party, else the
+ * first input's); every non-survivor input is removed. If the player's nation
+ * was a non-survivor input the player pointer is re-pointed to the survivor.
+ */
+export interface MergeOp {
+  kind: 'merge';
+  /** The id/name of every nation folded into the result. */
+  nationRefs: string[];
+  /** The id/name of the nation that survives and keeps its identity. */
+  survivingRef: string;
+  /** The name to give the merged nation. */
+  into: string;
+}
+
+/**
+ * A structural operation on the set of nations that the LLM may propose in a
+ * turn (`TurnResult.nationOps`). See the section comment above for the hybrid
+ * propose→confirm semantics. All three kinds are implemented: rename (P4a),
+ * and split / merge (P4b, v0.24).
+ */
+export type NationOp = RenameOp | SplitOp | MergeOp;
+
 /** One narrative event the LLM proposes for this turn. */
 export interface TurnEventSpec {
   nation: string;
@@ -39,6 +116,100 @@ export interface TurnEventSpec {
   outcome: EventOutcome;
 }
 
+// --- Map markers (v0.27, #44) -------------------------------------------------
+//
+// The LLM places named point markers (cities, factories, armies, ports,
+// capitals, fleets, rocket launch sites, gatherings) anchored to a region
+// key. It never sees or sets coordinates: the engine derives the position
+// from the region's precomputed centroid (public/region-centroids.json) plus a
+// small deterministic offset, and it recomputes each marker's owner from the
+// region's current owner on every turn (a released region → null).
+//
+// The marker id is a STABLE, deterministic 4-letter code (FNV-1a 32-bit →
+// base 26, the same scheme as the region keys' 4-char suffix) derived from
+// (type, name, regionKey) — so re-adding an identical marker is idempotent
+// (same id, skipped) and removing by id is unambiguous.
+
+/** The spec the LLM emits to place a marker: type, name and the region it sits in. */
+export interface MarkerSpec {
+  type: MarkerType;
+  name: string;
+  regionKey: string;
+}
+
+/**
+ * One existing marker as the user prompt presents it to the model (v0.27,
+ * #44): its stable `id` (the model may echo it in `TurnResult.markers.remove`),
+ * type, name, region key, and the id of the nation currently owning its
+ * region (`null` when the region is unowned / no man's land).
+ */
+export interface MarkerInfo {
+  id: string;
+  type: MarkerType;
+  name: string;
+  regionKey: string;
+  owner: string | null;
+}
+
+/**
+ * The per-type presentation of a marker: its display label (tooltip /
+ * dossier), its color, and its glyph character (a symbol-layer text label —
+ * a small, font-safe character in front of the name). Pure + shared so the
+ * client's marker layer and any server-side consumers agree on the look.
+ */
+export const MARKER_TYPE_INFO: Record<MarkerType, { label: string; color: string; glyph: string }> = {
+  city: { label: 'City', color: '#cbd5e1', glyph: '●' },
+  factory: { label: 'Factory', color: '#fb923c', glyph: '■' },
+  army: { label: 'Army', color: '#ef4444', glyph: '▲' },
+  port: { label: 'Port', color: '#38bdf8', glyph: '◆' },
+  capital: { label: 'Capital', color: '#fbbf24', glyph: '★' },
+  fleet: { label: 'Fleet', color: '#22d3ee', glyph: '◗' },
+  rocket: { label: 'Rocket site', color: '#a78bfa', glyph: '↥' },
+  gathering: { label: 'Gathering', color: '#4ade80', glyph: '◉' },
+};
+
+/** Hard cap on a game's total markers (new adds beyond the cap are dropped, v0.27 #44). */
+export const MAX_MARKERS = 400;
+
+/**
+ * FNV-1a 32-bit — the same tiny, stable, pure string hash the region keys use
+ * (see scripts/build-region-keys.mjs). Exported so the engine can derive
+ * deterministic per-axis jitter fractions from it (marker placement, v0.27 #44).
+ */
+export function fnv1a32(str: string): number {
+  let h = 0x811c9dc5;
+  for (let i = 0; i < str.length; i++) {
+    h ^= str.charCodeAt(i);
+    h = Math.imul(h, 0x01000193) >>> 0;
+  }
+  return h >>> 0;
+}
+
+/** Spread a 32-bit hash across four lowercase letters (base 26 per byte). */
+function code4(h: number): string {
+  let out = '';
+  for (let i = 0; i < 4; i++) {
+    out += String.fromCharCode(97 + (((h >>> (i * 8)) & 0xff) % 26));
+  }
+  return out;
+}
+
+/**
+ * The stable id for a marker: 4 base-26 lowercase chars from the FNV-1a hash
+ * of `(type, name, regionKey)` (NUL-separated so no field boundary is
+ * ambiguous). Deterministic across runs and platforms (pure string math), so
+ * the same (type, name, regionKey) always maps to the same id — re-adding is
+ * idempotent, removing by id is unambiguous.
+ */
+export function markerId(type: MarkerType, name: string, regionKey: string): string {
+  return code4(fnv1a32(`${type}\u0000${name}\u0000${regionKey}`));
+}
+
+/** True when `t` is one of the eight known marker types (v0.27, #44). */
+export function isMarkerType(t: unknown): t is MarkerType {
+  return typeof t === 'string' && (MARKER_TYPES as string[]).includes(t);
+}
+
 /** The exact JSON object the world-simulator LLM must return for a turn. */
 export interface TurnResult {
   date: string;
@@ -46,6 +217,36 @@ export interface TurnResult {
   stateChanges: StateChange[];
   relations: RelationChange[];
   territoryChanges: TerritoryChange[];
+  /**
+   * (v0.22, #16 P3) Region keys that become **unowned** — "no man's land" —
+   * this turn. The engine removes each key from its current (sole) owner so it
+   * ends the turn ownerless and marks it in `GameState.unowned`; the LLM
+   * narrates the cause (war, cataclysm, collapse) in `events`. Re-claiming is
+   * NOT expressed here: a nation re-claims an unowned region with an ordinary
+   * `gain` on that key. Only keys a nation currently owns can be released;
+   * empty on normal turns.
+   */
+  unowned: string[];
+  /**
+   * (v0.23 P4a / v0.24 P4b, #16) Nation-management ops the LLM proposes this
+   * turn. These are NOT applied by the turn: each is appended to
+   * `GameState.pendingNationOps` as a proposal awaiting the player's
+   * confirm/reject. All three kinds (rename, split, merge) are implemented —
+   * a confirmed rename changes `Nation.name`; a confirmed split dissolves the
+   * source into its parts; a confirmed merge folds its inputs into the
+   * survivor. Empty on turns where the model proposes none.
+   */
+  nationOps: NationOp[];
+  /**
+   * (v0.27, #44) Map-marker ops this turn. `add` places new named markers
+   * (the engine positions each at its region's centroid + a small
+   * deterministic offset, sets the owner to the region's post-turn owner,
+   * derives the stable id, and drops unknown types/region keys, duplicates,
+   * and adds beyond MAX_MARKERS); `remove` drops markers by their stable id
+   * (a no-op for an id that is not present). Both required, `[]` on turns
+   * with no marker activity.
+   */
+  markers: { add: MarkerSpec[]; remove: string[] };
 }
 
 /** Per-region map payload: region key -> owning nation + its stable color. */
@@ -152,6 +353,39 @@ export interface RemoveQueueItemResponse {
   game: GameState;
 }
 
+/**
+ * (v0.23 P4a / v0.24 P4b, #16) Confirm a pending nation-op proposal by its
+ * index in `game.pendingNationOps`. A rename takes effect (the player may
+ * override the proposed name via `edits.name`); a split and a merge are fully
+ * applied (v0.24 P4b). No LLM call, no turn advance.
+ */
+export interface ConfirmNationOpRequest {
+  index: number;
+  /**
+   * Optional player edits applied on confirm.
+   * - `name`: the final display name — overrides a rename's `to`, a merge's
+   *   `into`, or (for a split) the name of the part the player leads.
+   * - `playerPart`: for a split of the player's own nation, which part (index
+   *   into the op's `parts`) the player will lead (default `0` when missing or
+   *   out of range, so the player is never orphaned).
+   */
+  edits?: { name?: string; playerPart?: number };
+}
+export interface ConfirmNationOpResponse {
+  game: GameState;
+}
+
+/**
+ * (v0.23, #16 P4a) Reject (drop) a pending nation-op proposal by its index
+ * in `game.pendingNationOps` without applying it. No LLM call, no turn advance.
+ */
+export interface RejectNationOpRequest {
+  index: number;
+}
+export interface RejectNationOpResponse {
+  game: GameState;
+}
+
 export interface AdvisorRequest {
   /** Optional prompt to steer the brainstorm. */
   prompt?: string;
@@ -188,6 +422,47 @@ export function nationColor(id: string): string {
   return `hsl(${hue} 58% 46%)`;
 }
 
+// --- No man's land (v0.22, #16 P3) — the map presentation contract ---
+//
+// An unowned region has two distinct looks, and the difference is NOT in the
+// RegionMap (a key absent there is simply unowned): it is decided by the
+// client from `GameState.unowned` (the keys released mid-game). The constants
+// and the one decision function live here — shared and pure — so the
+// client's choropleth is the only consumer and the color contract is testable
+// from the server-side tests (shared/*.test.ts is not in the vitest glob).
+
+/** The distinct, visible neutral grey for a **no man's land** region (released mid-game). Hue-less by construction, so it can never collide with a nation's `nationColor` (`hsl(h 58% 46%)`, always chromatic). */
+export const NO_MANS_LAND_FILL = '#3f3f46';
+/** The border of a no-man's-land region (brighter than a plain unowned one). */
+export const NO_MANS_LAND_STROKE = 'rgba(255,255,255,0.25)';
+/** The faint neutral fill for a region no nation owns that was never released mid-game (a preset never assigned it). */
+export const UNOWNED_FILL = 'rgba(148,163,184,0.05)';
+/** The border of a plain unowned region. */
+export const UNOWNED_STROKE = 'rgba(255,255,255,0.14)';
+/** The border of an owned region (brighter than unowned). */
+export const OWNED_STROKE = 'rgba(255,255,255,0.30)';
+
+/** The hover-tooltip sub-line for a region with no owning nation. */
+export function unownedTooltipLabel(isNoMansLand: boolean): string {
+  return isNoMansLand ? "No man's land" : 'No owner';
+}
+
+/**
+ * The fill + border for one sub-region, given its RegionMap entry
+ * (`undefined` = unowned) and whether its key is no man's land (released
+ * mid-game, i.e. in `GameState.unowned`). Pure + shared; see the section
+ * comment above for why the distinction is not encoded in the RegionMap.
+ */
+export function regionFillStyle(
+  owner: RegionOwner | undefined,
+  isNoMansLand: boolean,
+): { fill: string; stroke: string } {
+  if (owner) return { fill: owner.color, stroke: OWNED_STROKE };
+  return isNoMansLand
+    ? { fill: NO_MANS_LAND_FILL, stroke: NO_MANS_LAND_STROKE }
+    : { fill: UNOWNED_FILL, stroke: UNOWNED_STROKE };
+}
+
 /** Rebuild the full event list entry shape from a TurnEventSpec + turn/date. */
 export function makeEvent(
   spec: TurnEventSpec,

shared/types.ts

@@ -1,5 +1,9 @@
 // Domain types — the single source of truth shared by the frontend (src/), the
 // backend (server/), and the LLM prompt contract. No runtime dependencies here.
+// (The single `import type` below erases at compile time, so no runtime
+// dependency on protocol.ts is introduced — see the GameState.pendingNationOps
+// doc comment.)
+import type { NationOp } from './protocol';
 
 /** A nation's 0–100 status indices. Every value is clamped to 0–100 by the engine. */
 export interface NationStats {
@@ -64,6 +68,60 @@ export const EVENT_TYPES: EventType[] = [
 
 export type EventOutcome = 'success' | 'failure' | 'partial' | 'neutral';
 
+// --- Map markers (v0.27, #44) -------------------------------------------------
+//
+// Named point markers the LLM can place on the map (cities, factories, armies,
+// ports, capitals, fleets, rocket launch sites, political/social gatherings).
+// A marker is anchored to a **region key** (see `public/region-keys.json`): the
+// engine positions it at that region's precomputed centroid (with a small
+// deterministic offset) and its `ownerNationId` follows the region's current
+// owner (recomputed on every turn; `null` when the region is unowned / no
+// man's land). See protocol.ts for the LLM-facing `TurnResult.markers`
+// contract and the `markerId` derivation.
+
+/** The eight marker categories the model may place (v0.27, #44). */
+export type MarkerType =
+  | 'city'
+  | 'factory'
+  | 'army'
+  | 'port'
+  | 'capital'
+  | 'fleet'
+  | 'rocket'
+  | 'gathering';
+
+/** All marker types, in canonical order (used by the LLM contract + map layer). */
+export const MARKER_TYPES: MarkerType[] = [
+  'city',
+  'factory',
+  'army',
+  'port',
+  'capital',
+  'fleet',
+  'rocket',
+  'gathering',
+];
+
+/**
+ * A named point marker on the map (v0.27, #44). `id` is a stable,
+ * deterministic 4-character code derived from `type + name + regionKey`
+ * (see protocol.markerId) — re-adding the same marker is idempotent and
+ * removing by id is unambiguous. `lat`/`lon` are filled in by the engine from
+ * the region's centroid manifest (never by the model); `ownerNationId` is the
+ * marker's region's current owner (`null` when unowned) and is recomputed by
+ * the engine on every committed turn, so a marker always follows its region.
+ */
+export interface MapMarker {
+  id: string;
+  type: MarkerType;
+  name: string;
+  regionKey: string;
+  lat: number;
+  lon: number;
+  ownerNationId: string | null;
+  placedTurn: number;
+}
+
 /** A narrative event the simulation emitted on some turn. */
 export interface EventEntry {
   id: string;
@@ -120,6 +178,45 @@ export interface GameState {
    * in src/App.tsx. Starts at 1 on game creation.
    */
   version: GameVersion;
+  /**
+   * (v0.22, #16 P3) Region keys that became **unowned** — "no man's land" —
+   * during play: a region that was owned and was released to no owner by a
+   * committed turn (the LLM narrates the cause in that turn's events). This is
+   * deliberately distinct from the many regions a preset never assigns, which
+   * are also unowned but were never *released* mid-game; only the keys in this
+   * list render as the distinct visible no-man's-land grey (see
+   * protocol.regionFillStyle). A region leaves the list when any nation
+   * re-claims it (an ordinary `gain`). Always `[]` on a fresh game — no
+   * man's land can only arise mid-game. Rows saved before v0.22 load with
+   * this defaulted to `[]` (see server/db.ts).
+   */
+  unowned: string[];
+  /**
+   * (v0.23, #16 P4a; v0.24, #16 P4b) Nation-management ops the LLM has
+   * proposed but the player has not yet resolved: a *pending proposal* list,
+   * as opposed to `pending` (the current round's queued player actions). A
+   * turn NEVER applies one — `applyTurnResult` appends the turn's
+   * `nationOps` to this list, and each proposal survives across turns until
+   * the player resolves it: confirming applies it (a rename changes
+   * `Nation.name` only; a split partitions the nation's region-key territory
+   * into the new nations' territories; a merge folds the inputs' territory
+   * into the survivor) and removes it; rejecting removes it without
+   * applying. Always `[]` on a fresh game; rows saved before v0.23 load with
+   * this defaulted to `[]` (see server/db.ts). (The `NationOp` type lives in
+   * protocol.ts; the import there is type-only, so this file still has no
+   * runtime dependencies.)
+   */
+  pendingNationOps: NationOp[];
+  /**
+   * (v0.27, #44) Named point markers on the map: the LLM places them (via a
+   * turn's `markers.add`) and removes them (`markers.remove`, by id). The
+   * engine positions each at its region's centroid (deterministic small
+   * offset) and recomputes `ownerNationId` from the region's current owner on
+   * EVERY committed turn (a released region → `null`). Always `[]` on a fresh
+   * game; rows saved before v0.27 load with this defaulted to `[]` (see
+   * server/db.ts) — additive, no data wipe. Capped at protocol.MAX_MARKERS.
+   */
+  markers: MapMarker[];
 }
 
 /**

src/App.tsx

@@ -177,6 +177,10 @@ export default function App() {
   // gate the turn flow ("Jump forward" stays enabled while the advisor thinks) —
   // it only gates the advisor UI (the "Ask advisor" button + its hint).
   const [advisorBusy, setAdvisorBusy] = useState(false);
+  // Separate again: a pending nation-op confirm/reject is its own (fast,
+  // non-LLM) request. It gates only the nation-op dialog controls, never the
+  // turn flow — "Jump forward" stays usable while it is in flight.
+  const [opBusy, setOpBusy] = useState(false);
   // The id of the game the user is/was last in (mirrors localStorage) and the
   // list of saved games (newest first) shown on the home screen.
   const [activeGameId, setActiveGameId] = useState<string | null>(() => readActiveGameId());
@@ -401,6 +405,44 @@ export default function App() {
     [game, applyState],
   );
 
+  // Apply a pending nation op the model proposed (confirm; `edits.name`
+  // overrides a rename/merge name, `edits.playerPart` picks the player's
+  // successor part in a split). Fast, non-LLM — gated by `opBusy`, not `busy`.
+  // The version-bumped state comes back in the response and the SSE `state` event.
+  const runConfirmNationOp = useCallback(
+    async (index: number, edits?: { name?: string; playerPart?: number }) => {
+      if (!game) return;
+      setOpBusy(true);
+      try {
+        const { game: g } = await api.confirmNationOp(game.id, index, edits);
+        applyState(g);
+        toast.success('Nation change applied');
+      } catch (e) {
+        toastError(e);
+      } finally {
+        setOpBusy(false);
+      }
+    },
+    [game, applyState],
+  );
+
+  // Drop a pending nation op (reject / dismiss). Fast, non-LLM — `opBusy`.
+  const runRejectNationOp = useCallback(
+    async (index: number) => {
+      if (!game) return;
+      setOpBusy(true);
+      try {
+        const { game: g } = await api.rejectNationOp(game.id, index);
+        applyState(g);
+      } catch (e) {
+        toastError(e);
+      } finally {
+        setOpBusy(false);
+      }
+    },
+    [game, applyState],
+  );
+
   // Jump forward: the single LLM call that commits the pending round. Only this
   // sets `busy` (the adds above are fast and non-LLM).
   const runJump = useCallback(async () => {
@@ -507,12 +549,15 @@ export default function App() {
           regions={regions}
           busy={busy}
           advisorBusy={advisorBusy}
+          opBusy={opBusy}
           advisors={advisors}
           onAddAction={runAddAction}
           onAddDiplomacy={runAddDiplomacy}
           onRemoveQueueItem={runRemoveQueueItem}
           onAdvisor={askAdvisor}
           onJump={runJump}
+          onConfirmNationOp={runConfirmNationOp}
+          onRejectNationOp={runRejectNationOp}
           onHome={goHome}
         />
       </>
@@ -551,12 +596,16 @@ interface GameScreenProps {
   busy: boolean;
   /** An advisor fetch is in flight — drives the advisor UI only (never the turn). */
   advisorBusy: boolean;
+  /** A nation-op confirm/reject is in flight — drives the dialog controls only. */
+  opBusy: boolean;
   advisors: string[];
   onAddAction: (a: string) => void;
   onAddDiplomacy: (to: string, m: string) => void;
   onRemoveQueueItem: (index: number) => void;
   onAdvisor: (p?: string) => void;
   onJump: () => void;
+  onConfirmNationOp: (index: number, edits?: { name?: string; playerPart?: number }) => void;
+  onRejectNationOp: (index: number) => void;
   onHome: () => void;
 }
 
@@ -579,12 +628,15 @@ function GameScreen({
   regions,
   busy,
   advisorBusy,
+  opBusy,
   advisors,
   onAddAction,
   onAddDiplomacy,
   onRemoveQueueItem,
   onAdvisor,
   onJump,
+  onConfirmNationOp,
+  onRejectNationOp,
   onHome,
 }: GameScreenProps) {
   // Which nation's dossier to show. Defaults to the player; remounts per game.
@@ -653,6 +705,8 @@ function GameScreen({
         playerNationId={game.playerNationId}
         nations={game.nations}
         presetId={game.presetId}
+        unowned={game.unowned ?? []}
+        markers={game.markers ?? []}
         onFocusNation={focusNation}
       />
 
@@ -834,12 +888,15 @@ function GameScreen({
           game={game}
           busy={busy}
           advisorBusy={advisorBusy}
+          opBusy={opBusy}
           advisors={advisors}
           onAddAction={onAddAction}
           onAddDiplomacy={onAddDiplomacy}
           onRemoveQueueItem={onRemoveQueueItem}
           onAdvisor={onAdvisor}
           onJump={onJump}
+          onConfirmNationOp={onConfirmNationOp}
+          onRejectNationOp={onRejectNationOp}
           inWindow
         />
       </FloatingWindow>

src/components/ActionPanel.tsx

@@ -1,5 +1,5 @@
 import { useState } from 'react';
-import { Loader2, MessageSquare, Radar, Trash2, Zap } from 'lucide-react';
+import { Loader2, MessageSquare, PenLine, Radar, Trash2, Zap } from 'lucide-react';
 import { Badge } from './ui/badge';
 import { Button } from './ui/button';
 import { Card, CardContent, CardHeader, CardTitle } from './ui/card';
@@ -15,6 +15,7 @@ import { Input } from './ui/input';
 import { Textarea } from './ui/textarea';
 import { Tabs, TabsContent, TabsList, TabsTrigger } from './ui/tabs';
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from './ui/select';
+import NationOpDialog from './NationOpDialog';
 import type { GameState, RoundItem } from '@shared/types';
 
 interface Props {
@@ -27,6 +28,11 @@ interface Props {
    * never disable "Jump forward" or the rest of the turn flow.
    */
   advisorBusy: boolean;
+  /**
+   * A pending nation-op confirm/reject request is in flight. Distinct from
+   * `busy`: it gates only the nation-op dialog controls, never the turn flow.
+   */
+  opBusy: boolean;
   /** Advisor brainstorm suggestions from the last request. */
   advisors: string[];
   /** Queue a free-text action onto the pending round (no turn advance). */
@@ -38,6 +44,14 @@ interface Props {
   onAdvisor: (prompt?: string) => void;
   /** Commit the whole pending round in a single LLM turn. */
   onJump: () => void;
+  /**
+   * Apply a pending nation op: `edits.name` overrides a rename's target name
+   * (or a merge's name); `edits.playerPart` picks the player's successor part
+   * in a split (default 0).
+   */
+  onConfirmNationOp: (index: number, edits?: { name?: string; playerPart?: number }) => void;
+  /** Drop (reject) a pending nation op by its index. */
+  onRejectNationOp: (index: number) => void;
   /**
    * Render without the outer card chrome (the surrounding floating window
    * provides the border and the "Your move" title). Same content, same testids.
@@ -66,12 +80,15 @@ export default function ActionPanel({
   game,
   busy,
   advisorBusy,
+  opBusy,
   advisors,
   onAddAction,
   onAddDiplomacy,
   onRemoveQueueItem,
   onAdvisor,
   onJump,
+  onConfirmNationOp,
+  onRejectNationOp,
   inWindow = false,
 }: Props) {
   const [tab, setTab] = useState('action');
@@ -81,6 +98,8 @@ export default function ActionPanel({
   const [prompt, setPrompt] = useState('');
   // Index of the queued item the user is about to remove, or null (dialog closed).
   const [confirmRemoveIndex, setConfirmRemoveIndex] = useState<number | null>(null);
+  // Whether the nation-op review dialog is open.
+  const [opDialogOpen, setOpDialogOpen] = useState(false);
 
   const others = Object.entries(game.nations)
     .filter(([id]) => id !== game.playerNationId)
@@ -108,6 +127,7 @@ export default function ActionPanel({
   };
 
   const pending = game.pending;
+  const ops = game.pendingNationOps;
   // The item the confirmation dialog is about (re-derived from the live list,
   // so if the queue changes while the dialog is open it tracks the current
   // item at that index — or the dialog closes if the index went out of range).
@@ -325,6 +345,31 @@ export default function ActionPanel({
           </DialogContent>
         </Dialog>
 
+        {/* Pending nation ops proposed by the model — open to confirm or reject. */}
+        {ops.length > 0 && (
+          <button
+            type="button"
+            onClick={() => setOpDialogOpen(true)}
+            disabled={busy}
+            data-testid="nation-op-trigger"
+            className="flex w-full items-center justify-between gap-2 rounded-lg border border-amber-500/30 bg-amber-500/10 p-2.5 text-sm hover:bg-amber-500/15"
+          >
+            <span className="flex items-center gap-2 font-medium text-amber-300">
+              <PenLine className="size-4" />
+              {ops.length} nation {ops.length === 1 ? 'proposal' : 'proposals'} — review
+            </span>
+            <span className="text-xs text-amber-300/70">confirm or reject</span>
+          </button>
+        )}
+        <NationOpDialog
+          game={game}
+          open={opDialogOpen}
+          onOpenChange={setOpDialogOpen}
+          opBusy={opBusy}
+          onConfirm={onConfirmNationOp}
+          onReject={onRejectNationOp}
+        />
+
         <Button className="h-11 w-full" onClick={onJump} disabled={busy} data-testid="jump-forward">
           {busy ? <Loader2 className="size-4 animate-spin" /> : <Radar className="size-4" />}
           {queuedLabel}

src/components/NationOpDialog.tsx

@@ -0,0 +1,307 @@
+import { useState } from 'react';
+import { Check, Loader2, PenLine, X } from 'lucide-react';
+import { Button } from './ui/button';
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogHeader,
+  DialogTitle,
+} from './ui/dialog';
+import { Input } from './ui/input';
+import { Badge } from './ui/badge';
+import type { GameState } from '@shared/types';
+import type { NationOp, RenameOp } from '@shared/protocol';
+
+interface Props {
+  game: GameState;
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  /** A confirm/reject request is in flight — disable the per-op controls. */
+  opBusy: boolean;
+  /**
+   * Apply a pending op: `edits.name` overrides a rename's target name (or the
+   * merged name for a merge); `edits.playerPart` picks which new part the
+   * player's nation becomes in a split (default 0).
+   */
+  onConfirm: (index: number, edits?: { name?: string; playerPart?: number }) => void;
+  /** Drop a pending op (reject / dismiss). */
+  onReject: (index: number) => void;
+}
+
+/** A short, display-safe description of a pending nation op. */
+function describeOp(op: NationOp, name: (ref: string) => string): string {
+  if (op.kind === 'rename') return `Rename ${name(op.nationRef)} to “${op.to}”`;
+  if (op.kind === 'split')
+    return `Split ${name(op.nationRef)} into ${op.parts.length} nations (${op.parts
+      .map((p) => p.name)
+      .join(', ')})`;
+  return `Merge ${op.nationRefs.map(name).join(' + ')} into “${op.into}”`;
+}
+
+/**
+ * Reviews the nation ops the LLM has proposed (stored in `pendingNationOps`)
+ * and lets the player apply ("LLM proposes, player confirms") or drop each one:
+ * a rename shows the proposed name in an editable field; a split lists the
+ * proposed parts (with the number of regions each is assigned) and, when the
+ * split parent is the player's own nation, radio buttons to pick which new
+ * part the player leads; a merge shows the input nations (the survivor
+ * highlighted) and an editable name for the merged state (default `into`).
+ */
+export default function NationOpDialog({
+  game,
+  open,
+  onOpenChange,
+  opBusy,
+  onConfirm,
+  onReject,
+}: Props) {
+  const ops = game.pendingNationOps;
+  const name = (ref: string) => game.nations[ref]?.name ?? ref;
+  // Resolve a nation ref the way the server does (id first, then a unique
+  // case-insensitive name; null when unknown/ambiguous) — UI hints only, the
+  // server stays authoritative.
+  const resolveRef = (ref: string): string | null => {
+    const r = (ref ?? '').trim();
+    if (!r) return null;
+    if (game.nations[r]) return r;
+    const matches = Object.values(game.nations).filter(
+      (n) => n.name.trim().toLowerCase() === r.toLowerCase(),
+    );
+    return matches.length === 1 ? matches[0].id : null;
+  };
+  // The player's edits, keyed by pending-op index: the rename/merge target
+  // name (an unset entry means "use the model's proposed name"), and which
+  // split part the player succeeds to (preselected 0 — the radio is
+  // "required" and always has a valid answer).
+  const [edits, setEdits] = useState<Record<number, string>>({});
+  const [playerParts, setPlayerParts] = useState<Record<number, number>>({});
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="max-w-lg" data-testid="nation-op-dialog">
+        <DialogHeader>
+          <DialogTitle>
+            <span className="flex items-center gap-2">
+              <PenLine className="size-4 text-primary" />
+              Nation proposals
+            </span>
+          </DialogTitle>
+          <DialogDescription>
+            The model proposed changes to nations. Confirm to apply them (you can edit a
+            name and choose your successor state in a split) or reject to leave the world
+            as it is.
+          </DialogDescription>
+        </DialogHeader>
+
+        {ops.length === 0 ? (
+          <p className="py-2 text-sm text-muted-foreground" data-testid="nation-op-empty">
+            Nothing pending — the model hasn’t proposed any nation changes.
+          </p>
+        ) : (
+          <ul className="max-h-[50vh] space-y-2.5 overflow-y-auto pr-1" data-testid="nation-op-list">
+            {ops.map((op, i) => {
+              const isRename = op.kind === 'rename';
+              const isSplit = op.kind === 'split';
+              const isMerge = op.kind === 'merge';
+              const finalName = isRename ? (edits[i] ?? (op as RenameOp).to).trim() : '';
+              // Split: is the parent the player's own nation? (the successor radio
+              // is offered only in that case — the engine ignores playerPart otherwise)
+              const splitParentIsPlayer =
+                isSplit && resolveRef((op as { nationRef: string }).nationRef) === game.playerNationId;
+              const playerPart = playerParts[i] ?? 0;
+              // Merge: the survivor (highlighted) and whether the proposal is
+              // even valid (2+ distinct inputs; the survivor among them).
+              const survivorId = isMerge ? resolveRef((op as { survivingRef: string }).survivingRef) : null;
+              const inputIds = isMerge
+                ? new Set(
+                    (op as { nationRefs: string[] }).nationRefs
+                      .map(resolveRef)
+                      .filter((x): x is string => x !== null),
+                  )
+                : new Set<string>();
+              const mergeValid =
+                !isMerge || (inputIds.size >= 2 && (survivorId !== null && inputIds.has(survivorId)));
+              const mergeName = isMerge ? (edits[i] ?? (op as { into: string }).into).trim() : '';
+
+              const confirm = () => {
+                if (isRename) onConfirm(i, finalName ? { name: finalName } : undefined);
+                else if (isMerge) onConfirm(i, mergeName ? { name: mergeName } : undefined);
+                else onConfirm(i, splitParentIsPlayer ? { playerPart } : undefined);
+              };
+
+              return (
+                <li
+                  key={`${i}-${op.kind}`}
+                  className="rounded-lg border border-border/70 bg-card/50 p-3"
+                  data-testid="nation-op-item"
+                  data-kind={op.kind}
+                >
+                  <div className="mb-2 flex items-start gap-2">
+                    <Badge variant="secondary" className="shrink-0 text-[11px] capitalize">
+                      {op.kind}
+                    </Badge>
+                    <span className="min-w-0 flex-1 text-sm leading-snug">
+                      {describeOp(op, name)}
+                    </span>
+                  </div>
+
+                  {isRename ? (
+                    <div className="space-y-2.5">
+                      <Input
+                        value={edits[i] ?? (op as RenameOp).to}
+                        onChange={(e) => setEdits((p) => ({ ...p, [i]: e.target.value }))}
+                        placeholder="New name…"
+                        data-testid="nation-op-name-input"
+                      />
+                      <div className="flex justify-end gap-2">
+                        <Button
+                          variant="ghost"
+                          size="sm"
+                          onClick={() => onReject(i)}
+                          disabled={opBusy}
+                          className="text-muted-foreground hover:text-destructive"
+                          data-testid="nation-op-reject"
+                        >
+                          <X className="size-3.5" />
+                          Reject
+                        </Button>
+                        <Button
+                          size="sm"
+                          onClick={confirm}
+                          disabled={opBusy}
+                          data-testid="nation-op-confirm"
+                        >
+                          {opBusy ? <Loader2 className="size-3.5 animate-spin" /> : <Check className="size-3.5" />}
+                          Confirm
+                        </Button>
+                      </div>
+                    </div>
+                  ) : isSplit ? (
+                    <div className="space-y-2.5">
+                      <div className="space-y-1">
+                        {(op as { parts: { name: string; territory?: string[] }[] }).parts.map((p, pi) => (
+                          <div
+                            key={pi}
+                            className="flex items-center gap-2 text-sm"
+                            data-testid="nation-op-part"
+                            data-part={pi}
+                          >
+                            {splitParentIsPlayer ? (
+                              <input
+                                type="radio"
+                                name={`player-part-${i}`}
+                                checked={playerPart === pi}
+                                onChange={() => setPlayerParts((prev) => ({ ...prev, [i]: pi }))}
+                                disabled={opBusy}
+                                className="size-3.5 shrink-0 accent-amber-400"
+                                aria-label={`Make ${p.name} the player's successor state`}
+                                data-testid="nation-op-player-part"
+                              />
+                            ) : (
+                              <span className="size-3.5 shrink-0" aria-hidden />
+                            )}
+                            <span className="min-w-0 flex-1 truncate">{p.name}</span>
+                            <span className="shrink-0 text-[11px] tabular-nums text-muted-foreground">
+                              {p.territory?.length ?? 0} region{(p.territory?.length ?? 0) === 1 ? '' : 's'}
+                            </span>
+                          </div>
+                        ))}
+                      </div>
+                      {splitParentIsPlayer && (
+                        <p className="text-[11px] text-muted-foreground" data-testid="nation-op-split-hint">
+                          Choose which new state you will lead after the split.
+                        </p>
+                      )}
+                      {(op as { parts: unknown[] }).parts.length < 2 && (
+                        <p className="text-[11px] text-muted-foreground">
+                          This split names fewer than two parts — confirming will dismiss it
+                          without changing the world.
+                        </p>
+                      )}
+                      <div className="flex justify-end gap-2">
+                        <Button
+                          variant="ghost"
+                          size="sm"
+                          onClick={() => onReject(i)}
+                          disabled={opBusy}
+                          className="text-muted-foreground hover:text-destructive"
+                          data-testid="nation-op-reject"
+                        >
+                          <X className="size-3.5" />
+                          Reject
+                        </Button>
+                        <Button
+                          size="sm"
+                          onClick={confirm}
+                          disabled={opBusy}
+                          data-testid="nation-op-confirm"
+                        >
+                          {opBusy ? <Loader2 className="size-3.5 animate-spin" /> : <Check className="size-3.5" />}
+                          Confirm
+                        </Button>
+                      </div>
+                    </div>
+                  ) : (
+                    <div className="space-y-2.5">
+                      <div className="flex flex-wrap gap-1.5">
+                        {(op as { nationRefs: string[] }).nationRefs.map((ref, ri) => {
+                          const isSurvivor = resolveRef(ref) === survivorId;
+                          return (
+                            <Badge
+                              key={ri}
+                              variant={isSurvivor ? 'default' : 'secondary'}
+                              className="text-[11px]"
+                              data-testid="nation-op-input"
+                            >
+                              {name(ref)}
+                              {isSurvivor ? ' (survivor)' : ''}
+                            </Badge>
+                          );
+                        })}
+                      </div>
+                      <Input
+                        value={edits[i] ?? (op as { into: string }).into}
+                        onChange={(e) => setEdits((p) => ({ ...p, [i]: e.target.value }))}
+                        placeholder="New name…"
+                        data-testid="nation-op-name-input"
+                      />
+                      {!mergeValid && (
+                        <p className="text-[11px] text-muted-foreground">
+                          This merge is not valid as proposed — confirming will dismiss it
+                          without changing the world.
+                        </p>
+                      )}
+                      <div className="flex justify-end gap-2">
+                        <Button
+                          variant="ghost"
+                          size="sm"
+                          onClick={() => onReject(i)}
+                          disabled={opBusy}
+                          className="text-muted-foreground hover:text-destructive"
+                          data-testid="nation-op-reject"
+                        >
+                          <X className="size-3.5" />
+                          Reject
+                        </Button>
+                        <Button
+                          size="sm"
+                          onClick={confirm}
+                          disabled={opBusy}
+                          data-testid="nation-op-confirm"
+                        >
+                          {opBusy ? <Loader2 className="size-3.5 animate-spin" /> : <Check className="size-3.5" />}
+                          Confirm
+                        </Button>
+                      </div>
+                    </div>
+                  )}
+                </li>
+              );
+            })}
+          </ul>
+        )}
+      </DialogContent>
+    </Dialog>
+  );
+}

src/components/WorldMap.tsx

@@ -8,8 +8,16 @@ import 'maplibre-gl/dist/maplibre-gl.css';
 // Point it at a Vite-emitted copy of the worker module so it loads in prod.
 import workerUrl from 'maplibre-gl/dist/maplibre-gl-worker.mjs?url';
 maplibregl.setWorkerUrl(workerUrl);
-import { mapFeatureOwner, type RegionMap, type RegionOwner } from '@shared/protocol';
-import type { Nation } from '@shared/types';
+import {
+  mapFeatureOwner,
+  MARKER_TYPE_INFO,
+  nationColor,
+  regionFillStyle,
+  unownedTooltipLabel,
+  type RegionMap,
+  type RegionOwner,
+} from '@shared/protocol';
+import { MARKER_TYPES, type MapMarker, type Nation } from '@shared/types';
 import { cn } from '@/lib/utils';
 import { idToKey } from '@/lib/regions';
 
@@ -39,8 +47,16 @@ type GeoSource = maplibregl.GeoJSONSource;
 // looked black, and `styledata` was gated on fetching a remote document. An
 // inline object loads instantly, so `isStyleLoaded()` / `styledata` fire
 // immediately and the choropleth is guaranteed to paint. (The OFM `ne2sr`
-// raster has no vector tiles, so no glyphs endpoint is needed — we don't add
-// label layers; the choropleth provides the borders.)
+// raster has no vector tiles, so the basemap itself needs no label layers —
+// the choropleth provides the borders.)
+//
+// No `glyphs` URL: the map needs no MapLibre *text* rendering. The basemap is
+// raster (its labels are baked into the PNG tiles), and the LLM-placed map
+// markers (v0.27, #44) are drawn as canvas-generated icon images in a symbol
+// layer — fully self-contained, so they render offline and deterministically
+// without depending on any external font/glyph endpoint (the OpenFreeMap
+// `fonts/` path is a dead nginx 404, and the basemap's apparent labels come
+// from the raster, not from glyphs).
 const NE2SR_TILES = ['https://tiles.openfreemap.org/natural_earth/ne2sr/{z}/{x}/{y}.png'];
 
 const INLINE_STYLE: maplibregl.StyleSpecification = {
@@ -82,6 +98,8 @@ const PLAYER_LINE = 'player-line';
 const FLASH_LINE = 'flash-line';
 const HOVER_FILL = 'hover-fill';
 const HOVER_LINE = 'hover-line';
+const MARKERS_SOURCE = 'markers';
+const MARKER_SYMBOL = 'markers-symbol';
 
 /** Sensible per-scenario initial camera: Europe for the WWII scenarios, wider for the global ones. */
 function cameraForPreset(presetId: string): { center: [number, number]; zoom: number } {
@@ -114,19 +132,27 @@ function cameraForPreset(presetId: string): { center: [number, number]; zoom: nu
  *  - `regionKey` – the region key (e.g. `moselle-rygy`), the RegionMap key;
  *  - `fill`      – the owning nation's stable color (from `RegionMap[regionKey]`);
  *  - `owner`/`ownerId` – that nation's name/id (empty for an unowned region);
- *  - `stroke`    – a per-border alpha (owned brighter than unowned);
+ *  - `stroke`    – a per-border alpha (owned brightest, no man's land next,
+ *                  plain-unowned faintest);
  *  - `isPlayer`  – 1 when the owning nation is the player (drives the amber
  *                  player-highlight border).
  *
  * Crucially, the owner lookup keys the RegionMap by the stamped
  * `properties.regionKey`, **never** by the sub-region id or the repacked
  * top-level `id` — the RegionMap has no `FRA-03` entries, only region keys.
+ *
+ * (v0.22, #16 P3) Unowned regions have two looks, decided here (the
+ * RegionMap simply has no entry for them): a key in `unownedSet` — released to
+ * no man's land mid-game (`GameState.unowned`) — gets the distinct visible grey
+ * (`NO_MANS_LAND_FILL`); every other ownerless region keeps the faint
+ * preset-unassigned look. Both come from the shared `regionFillStyle` contract.
  */
 function applyRegions(
   geo: FeatureCollection,
   regions: RegionMap,
   playerNationId: string,
   idKey: Record<string, string>,
+  unownedSet: ReadonlySet<string>,
 ): FeatureCollection {
   const out: FeatureCollection = JSON.parse(JSON.stringify(geo));
   for (const f of out.features) {
@@ -141,14 +167,18 @@ function applyRegions(
     f.properties.regionKey = key;
     const r = key ? regions[key] : undefined;
     if (r) {
-      f.properties.fill = r.color;
+      const style = regionFillStyle(r, false);
+      f.properties.fill = style.fill;
+      f.properties.stroke = style.stroke;
       f.properties.owner = r.owner;
       f.properties.ownerId = r.ownerId;
-      f.properties.stroke = 'rgba(255,255,255,0.30)';
       f.properties.isPlayer = r.ownerId === playerNationId ? 1 : 0;
     } else {
-      f.properties.fill = 'rgba(148,163,184,0.05)';
-      f.properties.stroke = 'rgba(255,255,255,0.14)';
+      // Ownerless: visible grey only for keys released mid-game (no man's
+      // land); a preset that never assigned this sub-region stays faint.
+      const style = regionFillStyle(undefined, key !== '' && unownedSet.has(key));
+      f.properties.fill = style.fill;
+      f.properties.stroke = style.stroke;
       f.properties.owner = '';
       f.properties.ownerId = '';
       f.properties.isPlayer = 0;
@@ -177,6 +207,186 @@ function featuresByRegionKeys(
   return { type: 'FeatureCollection', features: JSON.parse(JSON.stringify(features)) };
 }
 
+// --- Map markers (v0.27, #44) ------------------------------------------------
+//
+// The LLM places named point markers (cities, factories, armies, ports,
+// capitals, fleets, rocket sites, gatherings) anchored to a region key. The
+// engine positions each at its region's centroid (deterministic small offset)
+// and recomputes its owner from the region's current owner every turn. The
+// map renders them as a single top-most symbol layer: a per-type glyph
+// character in front of the name, per-type color, dark-theme halo.
+
+/**
+ * The GeoJSON behind the marker symbol layer: one Point per marker at
+ * `[lon, lat]`, carrying the stable id, type, name, its type's glyph, and the
+ * current owner's name + stable color (empty when the region is unowned).
+ * Pure; the caller passes the current marker list + nations record, so a
+ * renamed/removed owner is picked up on the next paint.
+ */
+function buildMarkersFC(markers: MapMarker[], nations: Record<string, Nation>): FeatureCollection {
+  const features = markers.map((m) => {
+    const owner = m.ownerNationId ? nations[m.ownerNationId] : undefined;
+    return {
+      type: 'Feature' as const,
+      geometry: { type: 'Point' as const, coordinates: [m.lon, m.lat] as [number, number] },
+      properties: {
+        id: m.id,
+        type: m.type,
+        name: m.name,
+        glyph: MARKER_TYPE_INFO[m.type]?.glyph ?? '',
+        owner: owner?.name ?? '',
+        ownerId: owner?.id ?? '',
+        ownerColor: owner ? nationColor(owner.id) : '',
+      },
+    };
+  });
+  return { type: 'FeatureCollection', features };
+}
+
+// Small canvas-path helpers for the marker icons (self-contained shapes — no
+// unicode/font dependency, so they render identically in any environment).
+function roundRectPath(
+  ctx: CanvasRenderingContext2D,
+  x: number,
+  y: number,
+  w: number,
+  h: number,
+  r: number,
+): void {
+  ctx.beginPath();
+  ctx.moveTo(x + r, y);
+  ctx.lineTo(x + w - r, y);
+  ctx.quadraticCurveTo(x + w, y, x + w, y + r);
+  ctx.lineTo(x + w, y + h - r);
+  ctx.quadraticCurveTo(x + w, y + h, x + w - r, y + h);
+  ctx.lineTo(x + r, y + h);
+  ctx.quadraticCurveTo(x, y + h, x, y + h - r);
+  ctx.lineTo(x, y + r);
+  ctx.quadraticCurveTo(x, y, x + r, y);
+  ctx.closePath();
+}
+
+function starPath(
+  ctx: CanvasRenderingContext2D,
+  cx: number,
+  cy: number,
+  spikes: number,
+  outer: number,
+  inner: number,
+): void {
+  let rot = (Math.PI / 2) * -1;
+  const step = Math.PI / spikes;
+  ctx.beginPath();
+  ctx.moveTo(cx + Math.cos(rot) * outer, cy + Math.sin(rot) * outer);
+  for (let i = 0; i < spikes; i++) {
+    rot += step;
+    ctx.lineTo(cx + Math.cos(rot) * inner, cy + Math.sin(rot) * inner);
+    rot += step;
+    ctx.lineTo(cx + Math.cos(rot) * outer, cy + Math.sin(rot) * outer);
+  }
+  ctx.closePath();
+}
+
+/**
+ * (v0.27, #44) Draw one marker-type icon into an offscreen canvas: a distinct
+ * shape per type, filled with the type's color from the shared
+ * `MARKER_TYPE_INFO` contract, with a dark outline for legibility on any
+ * choropleth fill. Added to the map as a named image and referenced by the
+ * symbol layer's `icon-image` — a real symbol layer, per-type color + form,
+ * with zero external font/glyph dependency.
+ */
+function drawMarkerIcon(type: MapMarker['type']): ImageData {
+  const S = 44;
+  const c = document.createElement('canvas');
+  c.width = S;
+  c.height = S;
+  const ctx = c.getContext('2d')!;
+  const cx = S / 2;
+  const cy = S / 2;
+  ctx.fillStyle = MARKER_TYPE_INFO[type]?.color ?? '#cbd5e1';
+  ctx.strokeStyle = '#0b1220';
+  ctx.lineWidth = 2.5;
+  ctx.lineJoin = 'round';
+  switch (type) {
+    case 'city':
+      ctx.beginPath();
+      ctx.arc(cx, cy, S * 0.3, 0, Math.PI * 2);
+      break;
+    case 'factory': {
+      const h = S * 0.5;
+      roundRectPath(ctx, cx - h / 2, cy - h / 2, h, h, 5);
+      break;
+    }
+    case 'army': {
+      const r = S * 0.34;
+      ctx.beginPath();
+      ctx.moveTo(cx, cy - r);
+      ctx.lineTo(cx + r, cy + r * 0.8);
+      ctx.lineTo(cx - r, cy + r * 0.8);
+      ctx.closePath();
+      break;
+    }
+    case 'port': {
+      const r = S * 0.36;
+      ctx.beginPath();
+      ctx.moveTo(cx, cy - r);
+      ctx.lineTo(cx + r, cy);
+      ctx.lineTo(cx, cy + r);
+      ctx.lineTo(cx - r, cy);
+      ctx.closePath();
+      break;
+    }
+    case 'capital':
+      starPath(ctx, cx, cy, 5, S * 0.36, S * 0.15);
+      break;
+    case 'fleet':
+    case 'gathering':
+      ctx.beginPath();
+      ctx.arc(cx, cy, S * 0.32, 0, Math.PI * 2);
+      break;
+    case 'rocket': {
+      const w = S * 0.14;
+      ctx.beginPath();
+      ctx.moveTo(cx, cy - S * 0.36);
+      ctx.lineTo(cx + S * 0.22, cy - S * 0.04);
+      ctx.lineTo(cx + w, cy - S * 0.04);
+      ctx.lineTo(cx + w, cy + S * 0.34);
+      ctx.lineTo(cx - w, cy + S * 0.34);
+      ctx.lineTo(cx - w, cy - S * 0.04);
+      ctx.lineTo(cx - S * 0.22, cy - S * 0.04);
+      ctx.closePath();
+      break;
+    }
+  }
+  ctx.fill();
+  ctx.stroke();
+  // fleet and gathering share a circle base; an inner mark tells them apart
+  // (fleet = a dark porthole dot, gathering = a white bullseye dot).
+  if (type === 'fleet' || type === 'gathering') {
+    ctx.beginPath();
+    ctx.arc(cx, cy, S * 0.13, 0, Math.PI * 2);
+    ctx.fillStyle = type === 'fleet' ? '#0b1220' : '#ffffff';
+    ctx.fill();
+  }
+  // Hand MapLibre the raw pixels (an untainted canvas, so getImageData is safe)
+  // rather than the canvas element — `addImage` accepts ImageData directly.
+  return ctx.getImageData(0, 0, S, S);
+}
+
+/** The hover tooltip for a marker: its type label + name, then the owner chip. */
+function markerTooltipHtml(
+  type: string,
+  name: string,
+  owner: string,
+  ownerColor: string,
+): string {
+  const label = MARKER_TYPE_INFO[type as MapMarker['type']]?.label ?? 'Marker';
+  const ownerLine = owner
+    ? `<div class="hm-popup-owner"><span class="hm-chip" style="background:${ownerColor}"></span>${esc(owner)}</div>`
+    : '<div class="hm-popup-sub">No owner</div>';
+  return `<div class="hm-popup"><div class="hm-popup-title">${esc(label)}: ${esc(name)}</div>${ownerLine}</div>`;
+}
+
 const esc = (s: string) =>
   s.replace(/[&<>"']/g, (c) => ({ '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c] as string));
 
@@ -188,14 +398,21 @@ function statRow(label: string, value?: number): string {
 /**
  * Compact hover tooltip: the sub-region's name, its **current owner**
  * (color-chipped), and 1–2 key stats. When the region's country has no owning
- * nation, a minimal "No owner" card is shown instead. The static
- * parent-country code (`properties.parent`) is deliberately NOT printed here —
- * it never updates when ownership is transferred, so only the live owner chip
- * (resolved from the RegionMap) is shown.
+ * nation, a minimal card is shown instead; its sub-line says "No man's land"
+ * for a region released mid-game (v0.22, #16 P3) and "No owner" for a region
+ * no preset ever assigned. The static parent-country code
+ * (`properties.parent`) is deliberately NOT printed here — it never updates
+ * when ownership is transferred, so only the live owner chip (resolved from
+ * the RegionMap) is shown.
  */
-function hoverHtml(subRegionName: string, region?: RegionOwner, nation?: Nation): string {
+function hoverHtml(
+  subRegionName: string,
+  region?: RegionOwner,
+  nation?: Nation,
+  noMansLand = false,
+): string {
   if (!region || !nation) {
-    return `<div class="hm-popup"><div class="hm-popup-title">${esc(subRegionName || 'Unclaimed')}</div><div class="hm-popup-sub">No owner</div></div>`;
+    return `<div class="hm-popup"><div class="hm-popup-title">${esc(subRegionName || 'Unclaimed')}</div><div class="hm-popup-sub">${unownedTooltipLabel(noMansLand)}</div></div>`;
   }
   const stats = [statRow('Mil', nation.stats.military), statRow('Eco', nation.stats.economy)].join('');
   return `<div class="hm-popup">
@@ -213,6 +430,14 @@ interface Props {
   /** The active scenario id, for a sensible initial camera. */
   presetId: string;
   className?: string;
+  /**
+   * (v0.22, #16 P3) Region keys currently in no man's land (released
+   * mid-game — `GameState.unowned`). Such regions render the distinct visible
+   * grey (vs the faint preset-unassigned look of every other ownerless
+   * region) and their hover tooltip says "No man's land" instead of "No
+   * owner".
+   */
+  unowned?: string[];
   /**
    * Called with a region's owning-nation id when a sub-region is clicked, so the
    * dossier switches to that nation. The optional `info` carries the clicked
@@ -221,6 +446,13 @@ interface Props {
    * component doc for the full behavior.
    */
   onFocusNation?: (id: string, info?: { name?: string }) => void;
+  /**
+   * (v0.27, #44) The game's named map markers (`GameState.markers`): the LLM
+   * places/removes them over time, the engine positions each at its region's
+   * centroid and keeps its owner in sync with the region's owner. Rendered as
+   * a top-most symbol layer (per-type glyph + name, per-type color).
+   */
+  markers?: MapMarker[];
 }
 
 /**
@@ -246,6 +478,25 @@ interface Props {
  * never from the raw sub-region id (not a RegionMap key). Unowned sub-regions
  * (no RegionMap entry for their key) simply do not change the dossier.
  *
+ * (v0.22, #16 P3) An unowned region renders two distinct ways: a key in the
+ * `unowned` prop (released to no man's land mid-game — `GameState.unowned`)
+ * gets the distinct visible grey with a "No man's land" tooltip sub-line; every
+ * other ownerless region (a preset never assigned it) keeps the faint look and
+ * a plain "No owner" sub-line. The colors/labels come from the shared
+ * `regionFillStyle` / `unownedTooltipLabel` contract in @shared/protocol.
+ *
+ * (v0.27, #44) LLM-placed **map markers** (`markers` prop = `GameState.markers`)
+ * render on a top-most symbol layer: each is its type's canvas-generated icon
+ * (a distinct shape, per-type color from the shared `MARKER_TYPE_INFO`
+ * contract, dark-outlined) at the engine-derived position (region centroid +
+ * small deterministic offset). The icons are drawn into named map images
+ * (`marker-<type>`), so there is no external font/glyph dependency and markers
+ * render offline and deterministically. Hovering a marker shows a tooltip
+ * (type label + name + owner chip); clicking one switches the dossier to the
+ * owning nation (no-op when the marker's region is unowned). The region
+ * hover/click handlers detect a marker under the cursor (MapLibre layer events
+ * have no propagation) and act on the marker's data.
+ *
  * Zoom and pan are driven directly by the user (MapLibre wheel/trackpad + drag)
  * — no floating control and no external API.
  */
@@ -255,7 +506,9 @@ export default function WorldMap({
   nations,
   presetId,
   className,
+  unowned,
   onFocusNation,
+  markers,
 }: Props) {
   const containerRef = useRef<HTMLDivElement>(null);
   const mapRef = useRef<maplibregl.Map | null>(null);
@@ -268,12 +521,16 @@ export default function WorldMap({
   const nationsRef = useRef(nations);
   const playerRef = useRef(playerNationId);
   const presetRef = useRef(presetId);
+  const unownedRef = useRef<Set<string>>(new Set(unowned ?? []));
   const onFocusNationRef = useRef(onFocusNation);
+  const markersRef = useRef<MapMarker[]>(markers ?? []);
   regionsRef.current = regions;
   nationsRef.current = nations;
   playerRef.current = playerNationId;
   presetRef.current = presetId;
+  unownedRef.current = new Set(unowned ?? []);
   onFocusNationRef.current = onFocusNation;
+  markersRef.current = markers ?? [];
 
   // Diffing state for the transient territory-change flash (owned by this component
   // so a resync with identical data never re-flashes).
@@ -381,6 +638,39 @@ export default function WorldMap({
     const onHover = (e: maplibregl.MapLayerMouseEvent) => {
       const f = e.features?.[0];
       if (!f) return;
+      // (v0.27, #44) A marker rendered on top of this region wins the hover.
+      // The region polygon is always beneath a marker, so this FILL_LAYER
+      // delegate fires in both cases; if a marker icon is under the cursor,
+      // show the marker's tooltip (name + type + owner) instead of the
+      // region's. `e.point` is the cursor's pixel position, so querying the
+      // marker layer there tests the icon's (small) hit area, not the whole
+      // region.
+      const markerHits = map.queryRenderedFeatures(e.point, { layers: [MARKER_SYMBOL] });
+      if (markerHits.length > 0) {
+        const mp = (markerHits[0].properties ?? {}) as {
+          type?: string;
+          name?: string;
+          owner?: string;
+          ownerColor?: string;
+        };
+        hoverPopup
+          .setLngLat(e.lngLat)
+          .setHTML(
+            markerTooltipHtml(
+              typeof mp.type === 'string' ? mp.type : '',
+              typeof mp.name === 'string' ? mp.name : '',
+              typeof mp.owner === 'string' ? mp.owner : '',
+              typeof mp.ownerColor === 'string' ? mp.ownerColor : '',
+            ),
+          )
+          .addTo(map);
+        map.getCanvas().style.cursor = 'pointer';
+        // A marker has no region outline to highlight; clear the previous one
+        // (and reset lastHoverId so moving back onto a region re-triggers it).
+        lastHoverId = null;
+        (map.getSource(HOVER_SOURCE) as GeoSource | undefined)?.setData(emptyFC());
+        return;
+      }
       const p = f.properties as { name?: string; regionId?: string };
       const subId = typeof p?.regionId === 'string' ? p.regionId : '';
       if (subId && subId !== lastHoverId) {
@@ -396,9 +686,14 @@ export default function WorldMap({
       }
       const region = mapFeatureOwner(regionsRef.current, f);
       const nation = region ? nationsRef.current[region.ownerId] : undefined;
+      // (v0.22, #16 P3) whether this region is no man's land (released
+      // mid-game), so the ownerless tooltip can say so.
+      const pKey = f.properties?.regionKey;
+      const noMansLand =
+        !region && typeof pKey === 'string' && pKey !== '' && unownedRef.current.has(pKey);
       hoverPopup
         .setLngLat(e.lngLat)
-        .setHTML(hoverHtml(p?.name ?? subId, region, nation))
+        .setHTML(hoverHtml(p?.name ?? subId, region, nation, noMansLand))
         .addTo(map);
       map.getCanvas().style.cursor = 'pointer';
     };
@@ -418,6 +713,19 @@ export default function WorldMap({
     const onClick = (e: maplibregl.MapLayerMouseEvent) => {
       const f = e.features?.[0];
       if (!f) return;
+      // (v0.27, #44) A marker under the cursor: focus its owning nation
+      // (identical to its region's owner — the engine keeps a marker's owner in
+      // sync with the region) and carry the marker's name into the dossier.
+      const markerHits = map.queryRenderedFeatures(e.point, { layers: [MARKER_SYMBOL] });
+      if (markerHits.length > 0) {
+        const mp = (markerHits[0].properties ?? {}) as { ownerId?: string; name?: string };
+        const owner = typeof mp.ownerId === 'string' ? mp.ownerId : '';
+        if (owner) {
+          const info = typeof mp.name === 'string' ? { name: mp.name } : undefined;
+          onFocusNationRef.current?.(owner, info);
+        }
+        return;
+      }
       const region = mapFeatureOwner(regionsRef.current, f);
       if (!region?.ownerId) return;
       // Carry the clicked sub-region's name so the dossier can show which region
@@ -449,6 +757,9 @@ export default function WorldMap({
       if (!map.getSource(FLASH_SOURCE)) {
         map.addSource(FLASH_SOURCE, { type: 'geojson', data: emptyFC() });
       }
+      if (!map.getSource(MARKERS_SOURCE)) {
+        map.addSource(MARKERS_SOURCE, { type: 'geojson', data: emptyFC() });
+      }
     };
 
     // Stamp ownership + colors onto the regions source (no-op until both the
@@ -458,7 +769,27 @@ export default function WorldMap({
       const idKey = idKeyRef.current;
       const src = map.getSource(REGIONS_SOURCE) as GeoSource | undefined;
       if (!geo || !idKey || !src) return;
-      src.setData(applyRegions(geo, regionsRef.current, playerRef.current, idKey));
+      src.setData(applyRegions(geo, regionsRef.current, playerRef.current, idKey, unownedRef.current));
+    };
+
+    // Stamp the current markers onto the marker source (v0.27, #44).
+    const paintMarkers = () => {
+      const src = map.getSource(MARKERS_SOURCE) as GeoSource | undefined;
+      if (!src) return;
+      src.setData(buildMarkersFC(markersRef.current, nationsRef.current));
+    };
+
+    // Register the eight canvas-generated marker-type icon images (v0.27, #44).
+    // Images are cleared on a style (re)load, so this is (re)run from
+    // `ensureLayers` (which fires on every `styledata`). Self-contained — no
+    // external font/glyph endpoint — so markers render offline and
+    // deterministically.
+    const ensureMarkerImages = async () => {
+      for (const type of MARKER_TYPES) {
+        const id = `marker-${type}`;
+        if (map.getImage(id)) continue;
+        await map.addImage(id, drawMarkerIcon(type));
+      }
     };
 
     const ensureLayers = async () => {
@@ -480,6 +811,7 @@ export default function WorldMap({
       }
       if (cancelled) return;
       paintRegions();
+      paintMarkers();
       if (!map.getLayer(FILL_LAYER)) {
         // The choropleth is the star: a high opacity so the vivid per-nation
         // colors read clearly even on the dark background / over the terrain.
@@ -506,8 +838,9 @@ export default function WorldMap({
       }
       // NOTE: layers are added in bottom→top order (each appends on top). The
       // stack is: fill, base borders, player border, territory-change flash,
-      // hover brighten, hover outline. Do not use a `beforeId` here — it throws
-      // if that layer does not exist yet on a fresh style load.
+      // hover brighten, hover outline, and (top-most) the LLM-placed map
+      // markers' symbol layer (v0.27, #44). Do not use a `beforeId` here — it
+      // throws if that layer does not exist yet on a fresh style load.
       if (!map.getLayer(PLAYER_LINE)) {
         map.addLayer({
           id: PLAYER_LINE,
@@ -541,6 +874,36 @@ export default function WorldMap({
           paint: { 'line-color': '#ffffff', 'line-width': 1.6, 'line-opacity': 0.9 },
         });
       }
+      // (v0.27, #44) The LLM-placed map markers: a top-most symbol layer.
+      // Each marker renders its type's canvas-generated icon (a distinct shape,
+      // per-type color from the shared MARKER_TYPE_INFO contract) with a dark
+      // outline for legibility on any choropleth fill. The icon images are
+      // self-contained (no external font/glyph endpoint), so markers render
+      // offline and deterministically. `icon-image` is `marker-<type>`, the
+      // named canvas images registered by `ensureMarkerImages` above.
+      await ensureMarkerImages();
+      if (!map.getLayer(MARKER_SYMBOL)) {
+        map.addLayer({
+          id: MARKER_SYMBOL,
+          type: 'symbol',
+          source: MARKERS_SOURCE,
+          layout: {
+            'icon-image': ['concat', 'marker-', ['get', 'type']],
+            'icon-size': 0.8,
+            'icon-allow-overlap': true,
+            'icon-ignore-placement': true,
+          },
+        });
+      }
+      // Marker interactions: the markers sit above the choropleth, but they
+      // deliberately share the region (FILL_LAYER) handlers registered below.
+      // MapLibre layer-scoped events are independent per-layer delegates (no
+      // propagation, no stopPropagation), so a marker-on-region would fire
+      // both a marker and a region handler. Instead the region handlers detect
+      // a marker under the cursor (see onHover/onClick) and act on the
+      // marker's data; clicking a marker focuses its owning nation via the
+      // same path as clicking its region (the marker's owner == its region's
+      // owner).
       map.off('mousemove', FILL_LAYER, onHover);
       map.off('mouseout', FILL_LAYER, onHoverOut);
       map.off('click', FILL_LAYER, onClick);
@@ -568,7 +931,9 @@ export default function WorldMap({
   // sub-region whose owner changed since the last update (a transient,
   // self-cleaning pulse). The diff is over the region-keyed RegionMap (v0.19
   // #16 P1); `animateFlash` lights up exactly the sub-region for each changed
-  // key.
+  // key. Re-runs when the no-man's-land set changes too (v0.22 #16 P3) so a
+  // release/re-claim repaints the grey even if the RegionMap diff alone
+  // wouldn't catch it.
   useEffect(() => {
     const map = mapRef.current;
     const geo = baseGeoRef.current;
@@ -578,10 +943,11 @@ export default function WorldMap({
     prevRegionsRef.current = cur;
     const wasPrimed = primedRef.current;
     if (Object.keys(cur).length > 0) primedRef.current = true;
+    const unownedSet = new Set(unowned ?? []);
 
     if (map && geo && idKey) {
       const src = map.getSource(REGIONS_SOURCE) as GeoSource | undefined;
-      if (src) void src.setData(applyRegions(geo, cur, playerNationId, idKey));
+      if (src) void src.setData(applyRegions(geo, cur, playerNationId, idKey, unownedSet));
     }
 
     if (wasPrimed && prev && idKey) {
@@ -589,9 +955,24 @@ export default function WorldMap({
       for (const key of new Set([...Object.keys(prev), ...Object.keys(cur)])) {
         if ((prev[key]?.ownerId ?? '') !== (cur[key]?.ownerId ?? '')) changed.add(key);
       }
+      // A release (owned → unowned) and a re-claim (unowned → owned) both show
+      // up as ownerId changes above, so they flash like any other transfer.
       if (changed.size > 0) flashApiRef.current?.([...changed]);
     }
-  }, [regions, playerNationId]);
+  }, [regions, playerNationId, unowned]);
+
+  // (v0.27, #44) Repaint the marker symbol layer whenever the marker list
+  // changes (a turn placed/removed markers) or the nations record changes
+  // (a confirmed rename/merge changes an owner's display name). No-op until
+  // the map + source exist (the mount effect's ensureLayers applies the
+  // current data once the layer structure is in place).
+  useEffect(() => {
+    const map = mapRef.current;
+    if (!map) return;
+    const src = map.getSource(MARKERS_SOURCE) as GeoSource | undefined;
+    if (!src) return;
+    src.setData(buildMarkersFC(markers ?? [], nations));
+  }, [markers, nations]);
 
   // Full-viewport, edge-to-edge background layer. `position: fixed` is set
   // inline because MapLibre's own stylesheet sets `.maplibregl-map` to

src/lib/api.ts

@@ -6,9 +6,11 @@ import type {
   AddActionResponse,
   AddDiplomacyResponse,
   AdvisorResponse,
+  ConfirmNationOpResponse,
   CreateGameResponse,
   DeleteGameResponse,
   GameSummary,
+  RejectNationOpResponse,
   RemoveQueueItemResponse,
   TurnResponse,
 } from '@shared/protocol';
@@ -60,6 +62,24 @@ export const api = {
       method: 'POST',
       body: JSON.stringify({ index }),
     }),
+  // (v0.23, #16 P4a; v0.24, #16 P4b) Confirm a pending nation-op proposal by
+  // its index in `game.pendingNationOps`: a rename takes effect (`edits.name`
+  // overrides the proposed name), a split partitions the nation's territory
+  // (`edits.playerPart` picks which part the player leads, default 0), and a
+  // merge folds its inputs into the survivor (`edits.name` overrides the
+  // merged name). Fast, non-LLM — no turn advance. Returns the updated game.
+  confirmNationOp: (id: string, index: number, edits?: { name?: string; playerPart?: number }) =>
+    req<ConfirmNationOpResponse>(`/api/games/${id}/nation-op/confirm`, {
+      method: 'POST',
+      body: JSON.stringify({ index, ...(edits ? { edits } : {}) }),
+    }),
+  // (v0.23, #16 P4a) Reject (drop) a pending nation-op proposal by index,
+  // without applying it. Fast, non-LLM — no turn advance. Returns the updated game.
+  rejectNationOp: (id: string, index: number) =>
+    req<RejectNationOpResponse>(`/api/games/${id}/nation-op/reject`, {
+      method: 'POST',
+      body: JSON.stringify({ index }),
+    }),
   // Commit the whole pending round (or an empty one) in a single LLM turn.
   jump: (id: string) =>
     req<TurnResponse>(`/api/games/${id}/jump`, {