chore: bump to v0.23.0 (nation-op rename, #16 P4a) + CHANGELOG

Wire the 'LLM proposes, player confirms' nation-rename flow end to end:
- server: POST /api/games/:id/nation-op/confirm|reject (404/400, version-bumped SSE state)
- client: confirmNationOp/rejectNationOp api helpers + NationOpDialog (editable rename) wired into the Action panel via a 'Nation proposals' trigger
- AGENTS.md: document the pendingNationOps mechanism, routes, nationRef resolution, stub-never-proposes

AGENTS.md

@@ -28,12 +28,19 @@ 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` (1,796 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.
 - 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 +52,33 @@ 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; 151 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    # 1,796 sub-regions, id=<ISO_A3>-<nn>, parent=ISO_A3 (the choropleth)
+│   ├── region-keys.json    # feature id -> region key, 1,796 entries (the ownership/LLM address space, #16 P1)
+│   └── region-adjacency.json # region key -> bordering region keys, 1,796 entries (the getNeighbours data, #16 P2)
+├── scripts/                # the geo/manifest data pipeline — .mjs (turf allowed HERE only;
+│   │                       #   never imported by .ts): generate → coarsen → cleanup → smooth →
+│   │                       #   fill-gaps → build-region-keys → build-region-adjacency
+│   └── *.test.ts           # turf-free vitest tests pinning the dataset + both 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) + 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 / applyNationOp / confirmNationOp / rejectNationOp, v0.23 #16 P4a)
+│   ├── 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 +95,8 @@ 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) or reject (v0.23 #16 P4a)
         ├── 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 +110,11 @@ 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/`; 151 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 build:region-keys` / `build:region-adjacency` | (re)generate the `public/region-keys.json` / `region-adjacency.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 +163,81 @@ 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).
+- **Nation ops — “LLM proposes, player confirms” (v0.23, #16 P4a).** `TurnResult.nationOps` (required
+  in the schema) carries the LLM’s proposed **`NationOp`s** — a discriminated union of `rename` /
+  `split` / `merge`. `rename` is fully applied; `split` and `merge` are **declared shapes only**
+  (accepted and stored as pending, but a no-op until P4b implements them). 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?}}`) or `.../nation-op/reject`
+  (`{index}`): `confirmNationOp` applies the op to a clone (a 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) 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) with
+  an editable rename name plus Confirm / Reject. The stub never proposes a nation op (`nationOps: []`),
+  so this path is covered by unit tests only (`server/engine.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), 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 +280,12 @@ 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 +325,10 @@ 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 — 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 +2,40 @@
 
 All notable changes to **History** are listed here, newest first.
 
+## 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": "0.23.0",
   "private": true,
   "type": "module",
   "description": "AI-driven alternate-history simulator — the LLM is the world engine (Pax Historia style).",
@@ -15,6 +15,7 @@
     "smooth:regions": "node scripts/smooth-regions.mjs",
     "fill:regions": "node scripts/fill-gaps.mjs",
     "build:region-keys": "node scripts/build-region-keys.mjs",
+    "build:region-adjacency": "node scripts/build-region-adjacency.mjs",
     "typecheck": "tsc --noEmit",
     "lint": "eslint .",
     "e2e": "playwright test"

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/region-adjacency.test.ts

@@ -0,0 +1,87 @@
+/**
+ * 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(1796);
+  });
+
+  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);
+  });
+});

server/db.test.ts

@@ -23,6 +23,8 @@ function makeState(id: string): GameState {
     events: [],
     pending: [],
     version: 1,
+    unowned: [],
+    pendingNationOps: [],
   };
 }
 
@@ -73,6 +75,28 @@ 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('delete removes a game by id and reports absence otherwise', () => {
     const db = openDb(':memory:');
     db.save(makeState('a'));

server/db.ts

@@ -39,7 +39,14 @@ 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 = [];
+        return state;
       } catch {
         return null;
       }

server/engine.test.ts

@@ -1,17 +1,24 @@
 import { describe, expect, it } from 'vitest';
 import type { GameState, Preset, RoundItem } from '../shared/types';
-import { makeEvent, type TurnResult } from '../shared/protocol';
-import type { LlmClient } from './llm';
+import { makeEvent, type NationOp, type TurnResult } from '../shared/protocol';
+import type { LlmClient, ToolDefinition, WireMessage } from './llm';
 import { makeStubLlmClient } from './stub';
 import {
   applyTurnResult,
   buildSystemPrompt,
   buildUserPrompt,
+  confirmNationOp,
+  GET_NEIGHBOURS_TOOL,
   isMeaningful,
+  makeNeighboursExecutor,
   parseTurnResult,
+  playerFrontier,
   queueRoundItem,
+  rejectNationOp,
   removeRoundItem,
+  resolveNationRef,
   runTurn,
+  validateNationOps,
   validateTurnResult,
 } from './engine';
 
@@ -75,6 +82,8 @@ function baseState(): GameState {
     events: [],
     pending: [],
     version: 1,
+    unowned: [],
+    pendingNationOps: [],
   };
 }
 
@@ -88,7 +97,10 @@ const validResult = JSON.stringify({
     { nation: 'de', stat: 'economy', op: 'add', value: 10 },
   ],
   relations: [{ a: 'uk', b: 'us', set: 'ally' }],
-  territoryChanges: [{ nation: 'de', gain: ['POL'], lose: [] }],
+  // v0.21 (#16 P2): DE gains the UK's GBR — the key has exactly one previous
+  // owner, so the transfer applies (since v0.22 #16 P3 a key owned by NOBODY
+  // would be re-claimed instead of ignored; a release lives in "unowned").
+  territoryChanges: [{ nation: 'de', gain: ['GBR'], lose: [] }],
 });
 
 describe('runTurn', () => {
@@ -109,8 +121,10 @@ describe('runTurn', () => {
     // relations are symmetric
     expect(state.nations.uk.relations.us).toBe('ally');
     expect(state.nations.us.relations.uk).toBe('ally');
-    // territory moved to DE
-    expect(state.nations.de.territory).toContain('POL');
+    // territory moved to DE: it gains GBR (the UK's sole previous owner) and
+    // the old owner correspondingly loses it (v0.21 #16 P2: one owner per key)
+    expect(state.nations.de.territory).toContain('GBR');
+    expect(state.nations.uk.territory).not.toContain('GBR');
     // one event appended, tagged with the turn that was resolved (1)
     expect(state.events).toHaveLength(1);
     expect(state.events[0].turn).toBe(1);
@@ -121,7 +135,8 @@ describe('runTurn', () => {
     // and the original state object is NOT mutated
     expect(original.turn).toBe(1);
     expect(original.nations.uk.stats.military).toBe(80);
-    expect(original.nations.de.territory).not.toContain('POL');
+    expect(original.nations.de.territory).not.toContain('GBR');
+    expect(original.nations.uk.territory).toContain('GBR');
   });
 
   it('clamps out-of-range stat values into 0-100', async () => {
@@ -329,6 +344,22 @@ describe('buildUserPrompt (batched round)', () => {
     const withoutRef = JSON.parse(buildUserPrompt(baseState(), [])) as { regions?: Record<string, string> };
     expect(withoutRef.regions).toBeUndefined();
   });
+
+  it('(v0.22 #16 P3) emits the no-man\'s-land list when provided (even when empty) and omits it otherwise', () => {
+    // runTurn always passes state.unowned (even []), so the field is present...
+    const withEmpty = JSON.parse(buildUserPrompt(baseState(), [], undefined, undefined, [])) as {
+      unowned?: string[];
+    };
+    expect(withEmpty.unowned).toEqual([]);
+    // ...and a populated list reaches the model verbatim (it knows what it can re-claim)
+    const withKeys = JSON.parse(
+      buildUserPrompt(baseState(), [], undefined, undefined, ['GBR', 'POL']),
+    ) as { unowned?: string[] };
+    expect(withKeys.unowned).toEqual(['GBR', 'POL']);
+    // but a caller that does not provide it keeps the legacy payload shape
+    const omitted = JSON.parse(buildUserPrompt(baseState(), [])) as { unowned?: string[] };
+    expect(omitted.unowned).toBeUndefined();
+  });
 });
 
 describe('queueRoundItem', () => {
@@ -399,6 +430,271 @@ describe('removeRoundItem', () => {
   });
 });
 
+describe('resolveNationRef (v0.23 #16 P4a)', () => {
+  it('resolves an exact id first (even if a name matches something else)', () => {
+    const state = baseState();
+    expect(resolveNationRef(state, 'de')).toBe('de');
+  });
+
+  it('resolves a unique name case-insensitively', () => {
+    const state = baseState();
+    expect(resolveNationRef(state, 'US')).toBe('us');
+    expect(resolveNationRef(state, ' uS ')).toBe('us'); // trimmed, case-insensitive
+  });
+
+  it('returns null for an ambiguous name (two nations share it)', () => {
+    const state = baseState();
+    state.nations.us.name = 'UK'; // now uk and us are both "UK"
+    expect(resolveNationRef(state, 'UK')).toBeNull();
+    // but the exact id still resolves
+    expect(resolveNationRef(state, 'uk')).toBe('uk');
+  });
+
+  it('returns null for an unknown or empty reference (never throws)', () => {
+    const state = baseState();
+    expect(resolveNationRef(state, 'zzz-not-a-nation')).toBeNull();
+    expect(resolveNationRef(state, '   ')).toBeNull();
+    expect(resolveNationRef(state, '')).toBeNull();
+  });
+});
+
+describe('validateNationOps (v0.23 #16 P4a)', () => {
+  it('parses a valid rename (trimmed, capped) and drops invalid ones', () => {
+    const ops = validateNationOps([
+      { kind: 'rename', nationRef: ' de ', to: 'Reich' },
+      { kind: 'rename', nationRef: 'uk', to: '' }, // empty to -> dropped
+      { kind: 'rename', to: 'no ref' }, // missing nationRef -> dropped
+      { kind: 'rename', nationRef: 'us' }, // missing to -> dropped
+      { kind: 'bogus-kind' }, // unknown kind -> ignored
+      'not-an-object',
+      null,
+    ]);
+    expect(ops).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
+  });
+
+  it('parses a valid split (parts with names kept, nameless parts dropped)', () => {
+    const ops = validateNationOps([
+      {
+        kind: 'split',
+        nationRef: 'de',
+        parts: [
+          { name: 'East', territory: ['DEU', ''] },
+          { name: '   ' }, // empty name -> part dropped
+          { name: 'West' },
+        ],
+      },
+    ]);
+    expect(ops).toEqual([
+      {
+        kind: 'split',
+        nationRef: 'de',
+        parts: [{ name: 'East', territory: ['DEU'] }, { name: 'West', territory: [] }],
+      },
+    ]);
+    // a split with no usable parts is dropped entirely
+    expect(validateNationOps([{ kind: 'split', nationRef: 'de', parts: [{ name: '' }] }])).toEqual([]);
+  });
+
+  it('parses a valid merge and drops malformed ones', () => {
+    const ops = validateNationOps([
+      { kind: 'merge', nationRefs: ['uk', 'us'], survivingRef: 'uk', into: 'Anglo-Saxon Union' },
+      { kind: 'merge', nationRefs: [], survivingRef: 'uk', into: 'X' }, // no refs -> dropped
+      { kind: 'merge', nationRefs: ['uk'], survivingRef: '', into: 'X' }, // no survivor -> dropped
+      { kind: 'merge', nationRefs: ['uk'], survivingRef: 'uk' }, // no into -> dropped
+    ]);
+    expect(ops).toEqual([
+      { kind: 'merge', nationRefs: ['uk', 'us'], survivingRef: 'uk', into: 'Anglo-Saxon Union' },
+    ]);
+  });
+
+  it('returns [] for non-array input and is never thrown by', () => {
+    expect(validateNationOps(undefined)).toEqual([]);
+    expect(validateNationOps('nope')).toEqual([]);
+    expect(validateNationOps({})).toEqual([]);
+  });
+
+  it('validateTurnResult carries validated nationOps through (and defaults to [] when absent)', () => {
+    const withOps = validateTurnResult({
+      date: '1939-09-03',
+      events: [],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: [],
+      nationOps: [{ kind: 'rename', nationRef: 'France', to: 'French Republic' }],
+    });
+    expect(withOps).not.toBeNull();
+    expect(withOps!.nationOps).toEqual([{ kind: 'rename', nationRef: 'France', to: 'French Republic' }]);
+
+    const without = validateTurnResult({ date: '1939-09-03', events: [], stateChanges: [] });
+    expect(without).not.toBeNull();
+    expect(without!.nationOps).toEqual([]);
+  });
+});
+
+describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
+  it('a proposed rename is NOT applied by the turn — it lands in pendingNationOps, name untouched', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, {
+      date: '1939-09-03',
+      events: [{ nation: 'de', type: 'political', title: 'Reunification', text: 'The nation is renamed.', outcome: 'success' }],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: [],
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }],
+    });
+    expect(next.nations.de.name).toBe('DE'); // still the old name
+    expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
+    expect(next.version).toBe(2);
+    // the input is not mutated
+    expect(state.nations.de.name).toBe('DE');
+    expect(state.pendingNationOps).toEqual([]);
+  });
+
+  it('pending proposals SURVIVE a subsequent turn (unlike the round queue) and new ones append', () => {
+    const state = baseState();
+    state.pendingNationOps = [{ kind: 'rename', nationRef: 'de', to: 'Reich' }]; // unresolved from turn N-1
+    const next = applyTurnResult(state, {
+      date: '1939-09-03',
+      events: [],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: [],
+      nationOps: [{ kind: 'rename', nationRef: 'us', to: 'USA' }], // new proposal this turn
+    });
+    expect(next.pendingNationOps).toEqual([
+      { kind: 'rename', nationRef: 'de', to: 'Reich' }, // the old one survived
+      { kind: 'rename', nationRef: 'us', to: 'USA' }, // the new one was appended
+    ]);
+  });
+
+  it('a legacy state without the pendingNationOps field accepts proposals (defaulted to [])', () => {
+    const state = baseState();
+    delete (state as { pendingNationOps?: NationOp[] }).pendingNationOps; // simulate a pre-v0.23 row
+    const next = applyTurnResult(state, {
+      date: '1939-09-03',
+      events: [],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: [],
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }],
+    });
+    expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
+  });
+});
+
+describe('confirmNationOp / rejectNationOp (v0.23 #16 P4a)', () => {
+  /**
+   * The pending list: op 0 is referenced by id ('de'); op 1 is referenced by
+   * NAME ('US' — the id is lowercase 'us'), so confirming it exercises the
+   * name-resolution path of resolveNationRef.
+   */
+  function stateWithPending(): GameState {
+    const s = baseState();
+    s.pendingNationOps = [
+      { kind: 'rename', nationRef: 'de', to: 'Reich' },
+      { kind: 'rename', nationRef: 'US', to: 'United States' },
+    ];
+    return s;
+  }
+
+  it('confirm applies a rename (name only — id/territory/relations/player pointer untouched) and removes the op, bumping the version', () => {
+    const state = stateWithPending();
+    const next = confirmNationOp(state, 0);
+    expect(next).not.toBeNull();
+    expect(next!.nations.de.name).toBe('Reich');
+    expect(next!.nations.de.id).toBe('de'); // id unchanged
+    expect(next!.nations.de.territory).toEqual(['DEU']); // territory unchanged
+    expect(next!.nations.uk.relations.de).toBe('hostile'); // relations (keyed by id) unchanged
+    expect(next!.playerNationId).toBe('uk'); // player pointer unchanged
+    expect(next!.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'US', to: 'United States' }]);
+    expect(next!.version).toBe(2);
+    // the input state is not mutated
+    expect(state.nations.de.name).toBe('DE');
+    expect(state.pendingNationOps).toHaveLength(2);
+    expect(state.version).toBe(1);
+  });
+
+  it('confirm with an edits.name override renames to the player-edited name', () => {
+    const next = confirmNationOp(stateWithPending(), 0, { name: 'Greater Reich' });
+    expect(next!.nations.de.name).toBe('Greater Reich');
+  });
+
+  it('confirm with an empty edits.name falls back to the proposed name', () => {
+    const next = confirmNationOp(stateWithPending(), 0, { name: '   ' });
+    expect(next!.nations.de.name).toBe('Reich');
+  });
+
+  it('confirm resolves the target by name (not just id) — case-insensitively', () => {
+    const next = confirmNationOp(stateWithPending(), 1); // nationRef 'US' is a name, not the id 'us'
+    expect(next).not.toBeNull();
+    expect(next!.nations.us.name).toBe('United States');
+  });
+
+  it('confirm is a no-op on the world for a P4b-kind op (split/merge) — the op is still removed', () => {
+    const state = baseState();
+    state.pendingNationOps = [{ kind: 'split', nationRef: 'de', parts: [{ name: 'East' }] }];
+    const next = confirmNationOp(state, 0);
+    expect(next).not.toBeNull();
+    expect(next!.nations).toEqual(state.nations); // the world is untouched
+    expect(next!.pendingNationOps).toEqual([]); // ...but the proposal was resolved
+    expect(next!.version).toBe(2);
+  });
+
+  it('confirm with an invalid index returns null and mutates nothing', () => {
+    const state = stateWithPending();
+    expect(confirmNationOp(state, -1)).toBeNull();
+    expect(confirmNationOp(state, 2)).toBeNull();
+    expect(confirmNationOp(state, 0.5)).toBeNull();
+    expect(state.nations.de.name).toBe('DE');
+    expect(state.version).toBe(1);
+  });
+
+  it('reject drops the proposal without applying it, bumping the version', () => {
+    const state = stateWithPending();
+    const next = rejectNationOp(state, 0);
+    expect(next).not.toBeNull();
+    expect(next!.nations.de.name).toBe('DE'); // unchanged
+    expect(next!.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'US', to: 'United States' }]);
+    expect(next!.version).toBe(2);
+    expect(state.pendingNationOps).toHaveLength(2); // input untouched
+  });
+
+  it('reject with an invalid index returns null and mutates nothing', () => {
+    const state = stateWithPending();
+    expect(rejectNationOp(state, -1)).toBeNull();
+    expect(rejectNationOp(state, 2)).toBeNull();
+    expect(state.pendingNationOps).toHaveLength(2);
+    expect(state.version).toBe(1);
+  });
+
+  it('an ambiguous/invalid nationRef is a no-op on confirm (the op is resolved, the world unchanged)', () => {
+    const state = baseState();
+    state.nations.us.name = 'UK'; // make "UK" ambiguous (uk and us)
+    state.pendingNationOps = [{ kind: 'rename', nationRef: 'UK', to: 'Empire' }];
+    const next = confirmNationOp(state, 0);
+    expect(next).not.toBeNull();
+    expect(next!.nations.uk.name).toBe('UK'); // neither nation was renamed
+    expect(next!.nations.us.name).toBe('UK');
+    expect(next!.pendingNationOps).toEqual([]);
+  });
+});
+
+describe('buildSystemPrompt (nationOps contract, v0.23 #16 P4a)', () => {
+  it('both modes contract the nationOps field and the rename proposal rule', () => {
+    for (const p of [buildSystemPrompt(preset), buildSystemPrompt(preset, true)]) {
+      // the JSON shape carries the field in both modes
+      expect(p).toMatch(/"nationOps": \[\{"kind":"rename","nationRef":"<nation id or name>","to":"<new name>"\}\]/);
+      // the rule explains that it is a proposal only the player can confirm
+      expect(p).toMatch(/PROPOSAL/);
+      expect(p).toMatch(/only takes effect if the player confirms/);
+    }
+  });
+});
+
 describe('parseTurnResult', () => {
   it('parses a fenced JSON block', () => {
     const r = parseTurnResult('```json\n{"date":"1939-09-03","events":[{"nation":"uk","type":"military","title":"t","text":"b","outcome":"success"}]}\n```');
@@ -451,6 +747,8 @@ describe('applyTurnResult', () => {
       stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 99 }],
       relations: [],
       territoryChanges: [],
+      unowned: [],
+      nationOps: [],
     };
     applyTurnResult(state, result);
     expect(JSON.stringify(state)).toBe(snapshot);
@@ -465,6 +763,8 @@ describe('applyTurnResult', () => {
       stateChanges: [],
       relations: [],
       territoryChanges: [],
+      unowned: [],
+      nationOps: [],
     };
     const next = applyTurnResult(state, result);
     expect(next.pending).toEqual([]);
@@ -475,6 +775,8 @@ describe('applyTurnResult', () => {
 
   it('with a validKeys set: applies real region keys, ignores hallucinated ones', () => {
     const state = baseState();
+    // give the fixture's uk a real key ('wales-bbbb') for DE to be able to take
+    state.nations.uk.territory = ['GBR', 'wales-bbbb'];
     const result: TurnResult = {
       date: '1939-09-03',
       events: [],
@@ -483,9 +785,11 @@ describe('applyTurnResult', () => {
       // 'wales-bbbb' is a real key (owned by uk in the fixture); 'not-a-region-xyz'
       // is not a real key at all. Both are proposed as a gain by DE.
       territoryChanges: [{ nation: 'de', gain: ['wales-bbbb', 'not-a-region-xyz'], lose: [] }],
+      unowned: [],
+      nationOps: [],
     };
     const next = applyTurnResult(state, result, new Set(['wales-bbbb']));
-    // the valid key was gained (stolen from its owner); the bogus one was ignored
+    // the valid key was gained (taken from its sole previous owner); the bogus one was ignored
     expect(next.nations.de.territory).toContain('wales-bbbb');
     expect(next.nations.uk.territory).not.toContain('wales-bbbb');
     // the bogus key never entered any nation's territory
@@ -496,23 +800,561 @@ describe('applyTurnResult', () => {
 
   it('without a validKeys set: applies every listed key (legacy/unit path)', () => {
     const state = baseState();
+    state.nations.uk.territory = ['GBR', 'wales-bbbb'];
     const result: TurnResult = {
       date: '1939-09-03',
       events: [],
       stateChanges: [],
       relations: [],
+      // 'wales-bbbb' has a sole previous owner (uk) -> it transfers; 'POL' is
+      // owned by no one -> a re-claim (v0.22, #16 P3): DE gains it. It was never
+      // released (not in state.unowned), so it does not enter GameState.unowned.
       territoryChanges: [{ nation: 'de', gain: ['POL', 'wales-bbbb'], lose: [] }],
+      unowned: [],
+      nationOps: [],
     };
     const next = applyTurnResult(state, result); // no validKeys -> nothing filtered
-    expect(next.nations.de.territory).toContain('POL');
     expect(next.nations.de.territory).toContain('wales-bbbb');
+    expect(next.nations.uk.territory).not.toContain('wales-bbbb');
+    expect(next.nations.de.territory).toContain('POL'); // re-claimed, not ignored
+    expect(next.unowned).toEqual([]); // never released -> not no man's land
+  });
+});
+
+describe('applyTurnResult (sole-ownership invariants, v0.21 #16 P2)', () => {
+  const noEvents = {
+    date: '1939-09-03',
+    events: [],
+    stateChanges: [],
+    relations: [],
+    unowned: [],
+    nationOps: [],
+  };
+
+  it('a double claim (two different gainers, one key) is rejected: the key stays with its original owner', () => {
+    const state = baseState();
+    state.nations.uk.territory = ['GBR', 'wales-bbbb'];
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [
+        { nation: 'de', gain: ['wales-bbbb'], lose: [] },
+        { nation: 'us', gain: ['wales-bbbb'], lose: [] },
+      ],
+    });
+    expect(next.nations.uk.territory).toContain('wales-bbbb');
+    expect(next.nations.de.territory).not.toContain('wales-bbbb');
+    expect(next.nations.us.territory).not.toContain('wales-bbbb');
+  });
+
+  it('duplicate gain entries for the SAME nation are deduped (one claim, one copy)', () => {
+    const state = baseState();
+    state.nations.uk.territory = ['GBR', 'wales-bbbb'];
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [
+        { nation: 'de', gain: ['wales-bbbb'], lose: [] },
+        { nation: 'de', gain: ['wales-bbbb'], lose: [] },
+      ],
+    });
+    expect(next.nations.de.territory.filter((k) => k === 'wales-bbbb')).toHaveLength(1);
+    expect(next.nations.uk.territory).not.toContain('wales-bbbb');
+  });
+
+  it('a lone "lose" is a no-op: the key cannot be orphaned (zero owners)', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'uk', gain: [], lose: ['GBR'] }],
+    });
+    expect(next.nations.uk.territory).toContain('GBR');
+  });
+
+  it('a self-gain is a no-op (a nation keeps exactly one copy of its own key)', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'uk', gain: ['GBR'], lose: [] }],
+    });
+    expect(next.nations.uk.territory.filter((k) => k === 'GBR')).toHaveLength(1);
+  });
+
+  it('a pre-existing double ownership is never touched (a key with 2 owners keeps 2)', () => {
+    const state = baseState();
+    state.nations.us.territory = ['USA', 'GBR']; // uk AND us already share GBR
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'de', gain: ['GBR'], lose: [] }],
+    });
+    expect(next.nations.uk.territory).toContain('GBR');
+    expect(next.nations.us.territory).toContain('GBR');
+    expect(next.nations.de.territory).not.toContain('GBR');
+  });
+
+  it('ownership is conserved across a transfer: exactly one owner before and after', () => {
+    const state = baseState();
+    state.nations.uk.territory = ['GBR', 'wales-bbbb'];
+    const count = (s: GameState) =>
+      Object.values(s.nations).reduce(
+        (acc, n) => acc + n.territory.filter((k) => k === 'wales-bbbb').length,
+        0,
+      );
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'de', gain: ['wales-bbbb'], lose: [] }],
+    });
+    expect(count(state)).toBe(1);
+    expect(count(next)).toBe(1);
+    expect(next.nations.de.territory).toContain('wales-bbbb');
+    expect(next.nations.uk.territory).not.toContain('wales-bbbb');
+  });
+});
+
+describe('applyTurnResult (no man\'s land, v0.22 #16 P3)', () => {
+  const noEvents = {
+    date: '1939-09-03',
+    events: [],
+    stateChanges: [],
+    relations: [],
+    territoryChanges: [],
+    unowned: [],
+    nationOps: [],
+  };
+
+  it('a release removes the key from its sole owner and marks it in GameState.unowned', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['GBR'] });
+    expect(next.nations.uk.territory).not.toContain('GBR');
+    expect(next.unowned).toEqual(['GBR']);
+    // nothing else moved
+    expect(next.nations.us.territory).toEqual(['USA']);
+    expect(next.nations.de.territory).toEqual(['DEU']);
+  });
+
+  it('a re-claim (a gain on a currently-unowned key) grants it and removes it from GameState.unowned', () => {
+    const state = baseState();
+    state.unowned = ['POL']; // released in an earlier turn
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'de', gain: ['POL'], lose: [] }],
+    });
+    expect(next.nations.de.territory).toContain('POL');
+    expect(next.unowned).toEqual([]); // it left no man's land
+  });
+
+  it('a release and a claim of the same key in one turn: the claim wins (the key is owned)', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'de', gain: ['GBR'], lose: [] }],
+      unowned: ['GBR'],
+    });
+    expect(next.nations.de.territory).toContain('GBR');
+    expect(next.nations.uk.territory).not.toContain('GBR');
+    expect(next.unowned).toEqual([]);
+  });
+
+  it('a double claim on a released key is rejected: the key stays in no man\'s land', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [
+        { nation: 'de', gain: ['GBR'], lose: [] },
+        { nation: 'us', gain: ['GBR'], lose: [] },
+      ],
+      unowned: ['GBR'], // released first, then both nations lunge for it
+    });
+    expect(next.nations.uk.territory).not.toContain('GBR'); // the release applied
+    expect(next.nations.de.territory).not.toContain('GBR'); // both claims rejected
+    expect(next.nations.us.territory).not.toContain('GBR');
+    expect(next.unowned).toEqual(['GBR']);
+  });
+
+  it('releasing a key no nation owns (a preset-unassigned region) is a no-op — no man\'s land can only arise from a real release', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['POL'] });
+    expect(next.unowned).toEqual([]);
+    for (const n of Object.values(next.nations)) expect(n.territory).not.toContain('POL');
+  });
+
+  it('releasing a key with two owners (a corrupt state) is a no-op', () => {
+    const state = baseState();
+    state.nations.us.territory = ['USA', 'GBR']; // uk AND us share GBR
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['GBR'] });
+    expect(next.nations.uk.territory).toContain('GBR');
+    expect(next.nations.us.territory).toContain('GBR');
+    expect(next.unowned).toEqual([]);
+  });
+
+  it('releasing a key already in no man\'s land is a no-op (it stays listed once)', () => {
+    const state = baseState();
+    state.unowned = ['POL'];
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['POL'] });
+    expect(next.unowned).toEqual(['POL']);
+  });
+
+  it('with a validKeys set: releasing a hallucinated key is a no-op', () => {
+    const state = baseState();
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['not-a-region-xyz'] }, new Set(['wales-bbbb']));
+    expect(next.unowned).toEqual([]);
+  });
+
+  it('a legacy state without the unowned field accepts a release (the result carries the field)', () => {
+    const state = baseState();
+    delete (state as { unowned?: string[] }).unowned; // simulate a pre-v0.22 row
+    const next = applyTurnResult(state, { ...noEvents, unowned: ['GBR'] });
+    expect(next.unowned).toEqual(['GBR']);
+    expect(next.nations.uk.territory).not.toContain('GBR');
+  });
+
+  it('a turn with no releases leaves the existing no man\'s land list unchanged', () => {
+    const state = baseState();
+    state.unowned = ['POL'];
+    const next = applyTurnResult(state, {
+      ...noEvents,
+      territoryChanges: [{ nation: 'de', gain: ['GBR'], lose: [] }],
+    });
+    expect(next.unowned).toEqual(['POL']);
+    expect(next.nations.de.territory).toContain('GBR');
+  });
+
+  it('validateTurnResult dedupes and filters the unowned list (trimmed non-empty strings only)', () => {
+    const r = validateTurnResult({
+      date: '1939-09-03',
+      events: [],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: [' a ', 'a', '', 42, null, ' b '],
+    });
+    expect(r).not.toBeNull();
+    expect(r!.unowned).toEqual(['a', 'b']);
+  });
+
+  it('a lone release is meaningful (it survives the retry/nudge path)', () => {
+    expect(
+      isMeaningful({ date: 'x', events: [], stateChanges: [], relations: [], territoryChanges: [], unowned: ['GBR'], nationOps: [] }),
+    ).toBe(true);
+  });
+
+  it('runTurn applies a release end-to-end: the model narrates it and the key leaves its owner', async () => {
+    const original = baseState();
+    original.pending = [{ kind: 'action', text: 'Scorch the earth on the retreat' }];
+    const releaseJson = JSON.stringify({
+      date: '1939-09-05',
+      events: [
+        {
+          nation: 'uk',
+          type: 'military',
+          title: 'A retreat through the wastelands',
+          text: 'The abandoned highlands burn and lie empty.',
+          outcome: 'partial',
+        },
+      ],
+      stateChanges: [],
+      relations: [],
+      territoryChanges: [],
+      unowned: ['GBR'],
+    });
+    const payloads: string[] = [];
+    const client: LlmClient = {
+      chat: async (messages) => {
+        const user = messages.find((m) => m.role === 'user');
+        if (user) payloads.push(user.content as string);
+        return releaseJson;
+      },
+      listModels: async () => [],
+    };
+    const { state } = await runTurn({ llm: client, preset, state: original, items: original.pending });
+    // the event landed and the release applied
+    expect(state.events).toHaveLength(1);
+    expect(state.events[0].title).toBe('A retreat through the wastelands');
+    expect(state.nations.uk.territory).not.toContain('GBR');
+    expect(state.unowned).toEqual(['GBR']);
+    // on the first turn the model was shown the (empty) no-man's-land list...
+    const first = JSON.parse(payloads[0]) as { unowned?: string[] };
+    expect(first.unowned).toEqual([]);
+    // ...and on the next turn it is shown the released key (so it can re-claim it)
+    const next = await runTurn({ llm: client, preset, state, items: [] });
+    const second = JSON.parse(payloads[1]) as { unowned?: string[] };
+    expect(second.unowned).toEqual(['GBR']);
+    // the repeated "release" of an already-unowned key is a no-op
+    expect(next.state.unowned).toEqual(['GBR']);
+  });
+});
+
+describe('makeNeighboursExecutor (v0.21 #16 P2)', () => {
+  const getNeighbours = (keys: string[]) => keys.map((k) => `nb-${k}`);
+
+  it('answers getNeighbours with the resolver output', () => {
+    const exec = makeNeighboursExecutor(getNeighbours);
+    expect(exec('getNeighbours', { regionKeys: ['a', 'b'] })).toBe(
+      JSON.stringify({ neighbours: ['nb-a', 'nb-b'] }),
+    );
+  });
+
+  it('degrades unknown tools, malformed args, and unknown keys without throwing', () => {
+    const exec = makeNeighboursExecutor(getNeighbours, new Set(['a']));
+    expect(exec('otherTool', {})).toBe(JSON.stringify({ error: 'unknown tool: otherTool' }));
+    expect(exec('getNeighbours', { regionKeys: 'not-an-array' })).toBe(
+      JSON.stringify({ neighbours: [] }),
+    );
+    expect(exec('getNeighbours', { regionKeys: ['a', 'zzz-not-valid'] })).toBe(
+      JSON.stringify({ neighbours: ['nb-a'] }), // the unknown key is filtered out
+    );
+  });
+});
+
+describe('playerFrontier (v0.21 #16 P2)', () => {
+  const adjacency: Record<string, string[]> = {
+    GBR: ['DEU', 'USA'],
+    GBR2: ['DEU'],
+    DEU: ['GBR', 'GBR2', 'USA'],
+    USA: ['GBR', 'DEU'],
+  };
+  const getNeighbours = (keys: string[]) =>
+    [...new Set(keys.flatMap((k) => adjacency[k] ?? []))]
+      .filter((k) => !keys.includes(k))
+      .sort();
+
+  it('is the sorted, deduped set of other-nation keys bordering the player', () => {
+    const state = baseState();
+    state.nations.uk.territory = ['GBR', 'GBR2']; // the player owns both
+    // DEU (de) and USA (us) border the player; deduped and sorted
+    expect(playerFrontier(state, getNeighbours)).toEqual(['DEU', 'USA']);
+  });
+
+  it('drops candidates the player itself owns (a sloppy resolver may report them)', () => {
+    const state = baseState();
+    state.nations.uk.territory = ['GBR', 'GBR2'];
+    const sloppy = () => ['GBR2', 'DEU'];
+    expect(playerFrontier(state, sloppy)).toEqual(['DEU']);
+  });
+
+  it('is empty when the player has no territory or no controllable border', () => {
+    const empty = baseState();
+    empty.nations.uk.territory = [];
+    expect(playerFrontier(empty, getNeighbours)).toEqual([]);
+    const noBorders = () => [];
+    expect(playerFrontier(baseState(), noBorders)).toEqual([]);
+  });
+});
+
+describe('runTurn (getNeighbours tool path, v0.21 #16 P2)', () => {
+  const adjacency: Record<string, string[]> = {
+    GBR: ['DEU'],
+    DEU: ['GBR', 'USA'],
+    USA: ['DEU'],
+  };
+  const getNeighbours = (keys: string[]) =>
+    [...new Set(keys.flatMap((k) => adjacency[k] ?? []))]
+      .filter((k) => !keys.includes(k))
+      .sort();
+
+  const finalTurn = JSON.stringify({
+    date: '1939-09-03',
+    events: [
+      {
+        nation: 'uk',
+        type: 'military',
+        title: 'The border region falls',
+        text: 'UK seizes the contiguous region.',
+        outcome: 'success',
+      },
+    ],
+    stateChanges: [],
+    relations: [],
+    // the player gains its only frontier region (DEU, owned by de)
+    territoryChanges: [{ nation: 'uk', gain: ['DEU'], lose: [] }],
+  });
+
+  /**
+   * A fake LlmClient implementing BOTH chat() and chatWithTools(). The
+   * chatWithTools fake plays the model's side of the protocol: it records
+   * the initial messages + tools, executes the scripted tool calls through
+   * the executor the engine handed it, and returns the final content.
+   */
+  function toolLlm(final: string, scriptedCalls: Array<{ name: string; args: Record<string, unknown> }>) {
+    const seen: {
+      firstMessages: WireMessage[];
+      tools: ToolDefinition[];
+      executorCalls: Array<{ name: string; args: Record<string, unknown>; result: string }>;
+      chatCalls: number;
+    } = { firstMessages: [], tools: [], executorCalls: [], chatCalls: 0 };
+    const client: LlmClient = {
+      chat: async (messages) => {
+        seen.chatCalls += 1;
+        seen.firstMessages = messages as WireMessage[];
+        return final;
+      },
+      listModels: async () => [],
+      chatWithTools: async (messages, tools, executeTool) => {
+        seen.firstMessages = messages;
+        seen.tools = tools;
+        for (const call of scriptedCalls) {
+          seen.executorCalls.push({ ...call, result: executeTool(call.name, call.args) });
+        }
+        return final;
+      },
+    };
+    return { client, seen };
+  }
+
+  it('uses chatWithTools with the tool, a frontier in the prompt, the wired executor, and applies the transfer', async () => {
+    const original = baseState();
+    original.pending = [{ kind: 'action', text: 'Seize the border region' }];
+    const { client, seen } = toolLlm(finalTurn, [
+      { name: 'getNeighbours', args: { regionKeys: ['GBR'] } },
+    ]);
+    const { state } = await runTurn({
+      llm: client,
+      preset,
+      state: original,
+      items: original.pending,
+      getNeighbours,
+    });
+
+    // the tool was offered and the system prompt advertises it
+    expect(seen.tools.map((t) => t.function.name)).toEqual([GET_NEIGHBOURS_TOOL.function.name]);
+    const system = seen.firstMessages[0] as { role: 'system'; content: string };
+    expect(system.content).toContain('getNeighbours');
+
+    // the user payload carries the player's frontier (DEU: the player's only
+    // controllable border, owned by de)
+    const user = seen.firstMessages[1] as { role: 'user'; content: string };
+    const payload = JSON.parse(user.content) as { frontier?: string[] };
+    expect(payload.frontier).toEqual(['DEU']);
+
+    // the executor the engine built answers from the resolver
+    expect(seen.executorCalls).toHaveLength(1);
+    expect(seen.executorCalls[0].args).toEqual({ regionKeys: ['GBR'] });
+    expect(seen.executorCalls[0].result).toBe(JSON.stringify({ neighbours: ['DEU'] }));
+
+    // chat() was never used on the tool path
+    expect(seen.chatCalls).toBe(0);
+
+    // the contiguous transfer was applied: uk gains DEU, de loses it
+    expect(state.nations.uk.territory).toContain('DEU');
+    expect(state.nations.de.territory).not.toContain('DEU');
+  });
+
+  it('falls back to plain chat() when the client lacks chatWithTools (no tool; the frontier hint stays in the prompt)', async () => {
+    const original = baseState();
+    const { client, seen } = toolLlm(validResult, []);
+    delete client.chatWithTools; // simulate a minimal client (chat only)
+    const { state } = await runTurn({
+      llm: client,
+      preset,
+      state: original,
+      items: original.pending,
+      getNeighbours,
+    });
+    expect(seen.chatCalls).toBe(1);
+    expect(seen.tools).toEqual([]); // the tool path was never entered
+    const system = seen.firstMessages[0] as { content: string };
+    expect(system.content).not.toContain('getNeighbours');
+    const user = seen.firstMessages[1] as { content: string };
+    const payload = JSON.parse(user.content) as { frontier?: string[] };
+    // the frontier hint stays (a resolver was given) even without the tool —
+    // it also tells the model which borders are realistically contestable
+    expect(payload.frontier).toEqual(['DEU']);
+    // the canned result still applied (GBR moved uk -> de)
+    expect(state.nations.de.territory).toContain('GBR');
+    expect(state.nations.uk.territory).not.toContain('GBR');
+  });
+});
+
+describe('deterministic stub (one contiguous conquest per turn, v0.21 #16 P2)', () => {
+  const adjacency: Record<string, string[]> = {
+    GBR: ['DEU'],
+    DEU: ['GBR', 'USA'],
+    USA: ['DEU'],
+  };
+  const getNeighbours = (keys: string[]) =>
+    [...new Set(keys.flatMap((k) => adjacency[k] ?? []))]
+      .filter((k) => !keys.includes(k))
+      .sort();
+
+  it('transfers the first frontier region to the player (and its owner loses it)', async () => {
+    const original = baseState();
+    original.pending = [{ kind: 'action', text: 'March on the border region' }];
+    const { state } = await runTurn({
+      llm: makeStubLlmClient(),
+      preset,
+      state: original,
+      items: original.pending,
+      getNeighbours,
+    });
+    expect(state.nations.uk.territory).toContain('DEU'); // frontier[0]
+    expect(state.nations.de.territory).not.toContain('DEU');
+    // the rest of the stub behavior is unchanged
+    expect(state.turn).toBe(2);
+    expect(state.date).toBe('1939-09-03');
+    expect(state.nations.uk.stats.military).toBe(85); // clamp(80 + 5)
+    expect(state.events).toHaveLength(1);
+  });
+
+  it('with an empty frontier (no controllable border, like the UK in wwii-1939): no transfer, the turn still advances', async () => {
+    const original = baseState();
+    original.pending = [{ kind: 'action', text: 'Hold the line' }];
+    const { state } = await runTurn({
+      llm: makeStubLlmClient(),
+      preset,
+      state: original,
+      items: original.pending,
+      getNeighbours: () => [], // no borders at all
+    });
+    expect(state.nations.uk.territory).toEqual(['GBR']); // untouched
+    expect(state.nations.de.territory).toEqual(['DEU']);
+    expect(state.nations.us.territory).toEqual(['USA']);
+    expect(state.turn).toBe(2);
+    expect(state.events).toHaveLength(1);
+  });
+});
+
+describe('buildSystemPrompt (tool mode, v0.21 #16 P2)', () => {
+  it('mentions the getNeighbours tool and the contiguity rules only when the tool is sent', () => {
+    const plain = buildSystemPrompt(preset);
+    expect(plain).not.toContain('getNeighbours');
+    expect(plain).toMatch(/Only change borders when war/i); // the legacy rule stays
+    const withTool = buildSystemPrompt(preset, true);
+    expect(withTool).toContain('getNeighbours');
+    expect(withTool).toMatch(/contiguous/i);
+    expect(withTool).toMatch(/frontier/i);
+    expect(withTool).not.toMatch(/Only change borders when war/i);
+  });
+
+  it('(v0.22 #16 P3) both modes contract the no-man\'s-land field (release + re-claim) and constrain it to owned keys', () => {
+    for (const p of [buildSystemPrompt(preset), buildSystemPrompt(preset, true)]) {
+      // the JSON shape carries the field in both modes
+      expect(p).toMatch(/"unowned": \["<region key>"\]/);
+      // the rule explains release (narrated in events) and re-claim (ordinary gain)
+      expect(p).toMatch(/no man's land/i);
+      expect(p).toMatch(/narrate the cause in "events"/);
+      expect(p).toMatch(/re-claims it with a "gain"/i);
+      // the hard constraint: only currently-owned keys may be released
+      expect(p).toMatch(/only region keys that a nation currently owns/);
+    }
   });
 });
 
 describe('isMeaningful', () => {
   it('is true with an event, false when everything is empty', () => {
-    expect(isMeaningful({ date: 'x', events: [{ nation: 'uk', type: 'military', title: 't', text: 'b', outcome: 'neutral' }], stateChanges: [], relations: [], territoryChanges: [] })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], relations: [], territoryChanges: [] })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], relations: [], territoryChanges: [] })).toBe(false);
+    expect(isMeaningful({ date: 'x', events: [{ nation: 'uk', type: 'military', title: 't', text: 'b', outcome: 'neutral' }], stateChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [] })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], relations: [], territoryChanges: [], unowned: [], nationOps: [] })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [] })).toBe(false);
+  });
+
+  it('(v0.23 #16 P4a) a turn that only proposes a nation-op is meaningful (it survives the retry/nudge path)', () => {
+    expect(
+      isMeaningful({
+        date: 'x',
+        events: [],
+        stateChanges: [],
+        relations: [],
+        territoryChanges: [],
+        unowned: [],
+        nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }],
+      }),
+    ).toBe(true);
   });
 });

server/engine.ts

@@ -19,10 +19,18 @@ import {
   isDateLike,
   makeEvent,
   nationForPrompt,
+  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 +38,128 @@ 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.
+ */
+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 +168,7 @@ 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 +176,20 @@ 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>"}]',
     '}',
     '',
     '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".',
+    '- To rename a nation, add {"kind":"rename","nationRef":"<nation id or name>","to":"<new name>"} to "nationOps". This is a PROPOSAL: it only takes effect if the player confirms it, so use it only when the narrative justifies it (a revolution, reunification, regime change) — at most 1-2 per turn — and narrate it in "events".',
     '- 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 +207,20 @@ 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[],
 ): string {
   const player = state.nations[state.playerNationId];
   const playerName = player?.name ?? state.playerNationId;
@@ -116,6 +257,8 @@ export function buildUserPrompt(
     roundInstruction,
   };
   if (regionReference) payload.regions = regionReference;
+  if (frontier !== undefined) payload.frontier = frontier;
+  if (noMansLand !== undefined) payload.unowned = noMansLand;
   return JSON.stringify(payload, null, 2);
 }
 
@@ -176,6 +319,53 @@ 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 +380,8 @@ export function validateTurnResult(input: unknown): TurnResult | null {
     stateChanges: [],
     relations: [],
     territoryChanges: [],
+    unowned: [],
+    nationOps: [],
   };
 
   if (Array.isArray(o.events)) {
@@ -265,12 +457,38 @@ 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);
+
   return result;
 }
 
-/** A turn is "meaningful" if it produced at least an event or a stat change. */
+/**
+ * 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
+  );
 }
 
 // --- Applying the delta -------------------------------------------------------
@@ -287,7 +505,11 @@ 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, and territory
+ * moves (including no-man's-land releases, v0.22 #16 P3). 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.
  */
 export function applyTurnResult(state: GameState, result: TurnResult, validKeys?: ReadonlySet<string>): GameState {
   const next: GameState = JSON.parse(JSON.stringify(state));
@@ -312,24 +534,104 @@ 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];
+  // (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 +666,109 @@ 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;
+}
+
+/**
+ * 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). Rename 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). An unresolvable or ambiguous
+ * `nationRef` is a silent no-op. Split and merge are declared for P4b and are
+ * a no-op until then — the op stays pending-free once the player resolves it,
+ * but the world does not change yet.
+ */
+export function applyNationOp(state: GameState, op: NationOp, edits?: { name?: string }): void {
+  if (op.kind !== 'rename') return; // split/merge: declared for P4b, not applied yet
+  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;
+}
+
+/**
+ * Confirm a pending nation-op proposal by index: apply it (a rename takes
+ * effect, optionally with a player-edited name; split/merge are a no-op until
+ * P4b) 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 },
+): 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 +779,54 @@ 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[];
 }): 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 } = 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.
+  const user = buildUserPrompt(state, items, regionReference, frontier, state.unowned ?? []);
   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)) {
@@ -408,6 +836,8 @@ export async function runTurn(opts: {
       stateChanges: [],
       relations: [],
       territoryChanges: [],
+      unowned: [],
+      nationOps: [],
     };
   }
 

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, expandCountriesToKeys, hasAdjacency, loadRegions, neighboursOf, referenceForKeys, validKeys } from './regions';
 import { createPresetStore } from './presets';
 import { openDb, type Db } from './db';
 
@@ -124,6 +126,14 @@ 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: [],
   };
   // v0.19 (#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 +230,34 @@ app.post('/api/games/:id/queue/remove', (req, res) => {
   res.json({ game: next });
 });
 
+// (v0.23, #16 P4a) Resolve a pending nation-op proposal (a rename the LLM
+// proposed in an earlier turn, waiting in game.pendingNationOps). 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 +273,17 @@ 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,
     });
     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 +47,8 @@ const state: GameState = {
   events: [],
   pending: [],
   version: 1,
+  unowned: [],
+  pendingNationOps: [],
 };
 
 // The RegionMap built from the fixture: the authoritative region key → owner source.
@@ -49,6 +63,16 @@ 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 +167,48 @@ 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

@@ -6,8 +6,10 @@ import path from 'node:path';
 import {
   allTerritoryKeys,
   expandCountriesToKeys,
+  hasAdjacency,
   hasRegionData,
   loadRegions,
+  neighboursOf,
   referenceForKeys,
   regionName,
   resetRegions,
@@ -84,11 +86,38 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
       events: [],
       pending: [],
       version: 1,
+      unowned: [],
+      pendingNationOps: [],
     };
     // 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([]);
+  });
+
   describe('graceful degradation with no region data', () => {
     beforeEach(() => resetRegions());
 
@@ -99,6 +128,9 @@ 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([]);
     });
   });
 
@@ -143,6 +175,15 @@ describe('loadRegions resolves the manifest per environment (dev public/ vs prod
     expect(validKeys().size).toBe(1796);
   });
 
+  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([]);
+  });
+
   it('returns false and no data when neither public/ nor dist/ holds the files', () => {
     const emptyRoot = path.join(base, 'empty');
     mkdirSync(emptyRoot, { recursive: true });

server/regions.ts

@@ -1,18 +1,23 @@
 // 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) — 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)
 //
-// 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 +37,30 @@ 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[]>;
 }
 
 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, and adjacency. 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). 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 base = [
     path.join(root, 'public'), // dev: Vite serves public/ at /
     path.join(root, 'dist'), // prod: Vite copies public/* -> dist/ (== clientDir)
@@ -78,7 +90,22 @@ 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 = {};
+      }
+    }
+
+    data = { idToKey, keyToInfo, keysByCountry, validKeys, adjacency };
     return validKeys.size > 0;
   } catch (err) {
     console.error('[regions] failed to load region data', err);
@@ -151,3 +178,30 @@ 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;
+}
+
+/**
+ * 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 +13,24 @@ 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[];
 }
 
 function truncate(s: string, n: number): string {
@@ -31,6 +45,22 @@ 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.
  */
 export function deterministicTurn(p: StubPayload): TurnResult {
   const state = p.state;
@@ -42,6 +72,23 @@ 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 +123,9 @@ 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)
   };
 }
 

shared/protocol.ts

@@ -30,6 +30,74 @@ export interface TerritoryChange {
   lose: string[];
 }
 
+// --- Nation-management ops (v0.23, #16 P4a: 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. Rename
+// is implemented in v0.23 (P4a); split and merge are declared here so the union
+// is stable for P4b, and are defensively accepted-but-not-applied until then.
+
+/**
+ * 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 (declared for #16 P4b; **not** applied by the engine yet
+ * — it is accepted into the pending list, but confirming it is a no-op until
+ * P4b lands). Describes the new nations a source nation is divided into.
+ */
+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 (declared for #16 P4b; **not** applied by the engine yet
+ * — accepted into the pending list, no-op on confirm until P4b). Folds several
+ * nations into a single surviving nation.
+ */
+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. Rename is implemented (P4a); split/merge are
+ * declared for P4b and are a safe no-op until then.
+ */
+export type NationOp = RenameOp | SplitOp | MergeOp;
+
 /** One narrative event the LLM proposes for this turn. */
 export interface TurnEventSpec {
   nation: string;
@@ -46,6 +114,25 @@ 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, #16 P4a) 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. Rename is the only kind the engine currently applies;
+   * split/merge are declared for P4b and are accepted-but-dropped. Empty on
+   * turns where the model proposes none.
+   */
+  nationOps: NationOp[];
 }
 
 /** Per-region map payload: region key -> owning nation + its stable color. */
@@ -152,6 +239,32 @@ export interface RemoveQueueItemResponse {
   game: GameState;
 }
 
+/**
+ * (v0.23, #16 P4a) 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`); split/merge proposals are a no-op on
+ * confirm until P4b. No LLM call, no turn advance.
+ */
+export interface ConfirmNationOpRequest {
+  index: number;
+  /** Optional player edits applied on confirm (rename: the final display name). */
+  edits?: { name?: string };
+}
+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 +301,47 @@ 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 {
@@ -120,6 +124,34 @@ 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) 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 — the id, its territory,
+   * its relations, and the player pointer all stay valid) and removes it;
+   * rejecting removes it without applying. Split/merge are declared for P4b
+   * and are a safe no-op on confirm until then. 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[];
 }
 
 /**

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 +405,43 @@ export default function App() {
     [game, applyState],
   );
 
+  // Apply a pending nation op the model proposed (confirm, with an optional
+  // rename-name edit). 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 }) => {
+      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 +548,15 @@ 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 +595,16 @@ 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 }) => void;
+  onRejectNationOp: (index: number) => void;
   onHome: () => void;
 }
 
@@ -579,12 +627,15 @@ 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 +704,7 @@ function GameScreen({
         playerNationId={game.playerNationId}
         nations={game.nations}
         presetId={game.presetId}
+        unowned={game.unowned ?? []}
         onFocusNation={focusNation}
       />
 
@@ -834,12 +886,15 @@ 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 +44,10 @@ 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` optionally overrides a rename. */
+  onConfirmNationOp: (index: number, edits?: { name?: string }) => 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 +76,15 @@ 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 +94,8 @@ 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 +123,7 @@ 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 +341,31 @@ 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 +1,156 @@
+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` optionally overrides a rename's target name. */
+  onConfirm: (index: number, edits?: { name?: string }) => 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 model's proposed name in an editable field (so the player
+ * can tweak it before confirming); split and merge are declared but not yet
+ * applied (P4b) — they can be dismissed but not confirmed.
+ */
+export default function NationOpDialog({
+  game,
+  open,
+  onOpenChange,
+  opBusy,
+  onConfirm,
+  onReject,
+}: Props) {
+  const ops = game.pendingNationOps;
+  const name = (ref: string) => game.nations[ref]?.name ?? ref;
+  // The player's edit to a rename's target name, keyed by pending-op index.
+  // An unset entry means "use the model's proposed name" (`op.to`).
+  const [edits, setEdits] = useState<Record<number, string>>({});
+
+  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
+            rename) 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 finalName = isRename ? (edits[i] ?? (op as RenameOp).to).trim() : '';
+              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={() => onConfirm(i, finalName ? { name: finalName } : undefined)}
+                          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="flex items-center justify-between gap-2">
+                      <span className="text-[11px] text-muted-foreground">
+                        {op.kind === 'split' ? 'Split' : 'Merge'} isn’t available yet — dismiss to ignore it.
+                      </span>
+                      <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" />
+                        Dismiss
+                      </Button>
+                    </div>
+                  )}
+                </li>
+              );
+            })}
+          </ul>
+        )}
+      </DialogContent>
+    </Dialog>
+  );
+}

src/components/WorldMap.tsx

@@ -8,7 +8,13 @@ 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 {
+  mapFeatureOwner,
+  regionFillStyle,
+  unownedTooltipLabel,
+  type RegionMap,
+  type RegionOwner,
+} from '@shared/protocol';
 import type { Nation } from '@shared/types';
 import { cn } from '@/lib/utils';
 import { idToKey } from '@/lib/regions';
@@ -114,19 +120,27 @@ 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 +155,18 @@ 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;
@@ -188,14 +206,21 @@ 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 +238,14 @@ 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
@@ -246,6 +279,13 @@ 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.
+ *
  * Zoom and pan are driven directly by the user (MapLibre wheel/trackpad + drag)
  * — no floating control and no external API.
  */
@@ -255,6 +295,7 @@ export default function WorldMap({
   nations,
   presetId,
   className,
+  unowned,
   onFocusNation,
 }: Props) {
   const containerRef = useRef<HTMLDivElement>(null);
@@ -268,11 +309,13 @@ 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);
   regionsRef.current = regions;
   nationsRef.current = nations;
   playerRef.current = playerNationId;
   presetRef.current = presetId;
+  unownedRef.current = new Set(unowned ?? []);
   onFocusNationRef.current = onFocusNation;
 
   // Diffing state for the transient territory-change flash (owned by this component
@@ -396,9 +439,14 @@ 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';
     };
@@ -458,7 +506,7 @@ 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));
     };
 
     const ensureLayers = async () => {
@@ -568,7 +616,9 @@ 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 +628,11 @@ 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 +640,11 @@ 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]);
 
   // 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 +62,21 @@ export const api = {
       method: 'POST',
       body: JSON.stringify({ index }),
     }),
+  // (v0.23, #16 P4a) Confirm a pending nation-op proposal by its index in
+  // `game.pendingNationOps` (a rename takes effect; `edits.name` overrides the
+  // proposed name). Fast, non-LLM — no turn advance. Returns the updated game.
+  confirmNationOp: (id: string, index: number, edits?: { name?: string }) =>
+    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`, {