feat: #65 sea control — 11th ability (v0.43.0)

Adds the sea ability: a fixed set of 12 named sea zones with sole-control semantics, contest-by-higher-military, and a deterministic per-turn +1 military/+1 economy bonus for each claimed zone. Durable (owns GameState.seaZones), additive migration, stub-inert (e2e unaffected). Fixes #65 Design note: Gitea #65 sketched a free-form 'naval' layer; the implemented approved design is this richer 'sea' layer with a fixed zone set.
Merge pull request 'feat(abilities): migration & refugees lever (v0.42.0, #64 )' (#77 ) from feat/64-migration into master
2026-10-16 12:50:22 +00:00 · 2026-10-16 12:20:03 +02:00 · 2026-10-16 10:15:45 +00:00
25 changed files with 2151 additions and 62 deletions
@@ -102,8 +102,9 @@ history/
 │   │   ├── shared.ts       #   shared helpers (stat dips / re-derive / ref resolution, …)
 │   │   ├── apply-helpers.ts  #   shared apply-path helpers
 │   │   ├── <name>.ts       #   one module per ability: wars / takeovers / leaders / nuclear /
-│   │   │                   #     ideology / industry / economy / hybrid / disasters (v0.41.0 #63)
+│   │   │                   #     ideology / industry / economy / hybrid / disasters (v0.41.0 #63) /
-│   │   ├── *.test.ts       #   per-ability unit tests (registry.test.ts pins the 9-ability contract)
+│   │   │                   #     migration (v0.42.0 #64)
 │   │   ├── *.test.ts       #   per-ability unit tests (registry.test.ts pins the 10-ability contract)
 │   │   └── goldens/        #   pinned prompt goldens (system-no-tool / system-tool / user)
 │   └── *.test.ts           # unit tests (vitest)
 └── src/
@@ -509,6 +510,79 @@ history/
  re-baselined in v0.41.0). `isMeaningful` is `events.length > 0`. The stub never proposes a
  disaster (`{ events: [] }`), so e2e (CI, `LLM_STUB=1`) is unaffected and the path is unit-tested
  only (`server/abilities/disasters.test.ts`).
 - **Migration & refugees — population flows between nations with a deterministic dip (v0.42.0, #64).**
  `TurnResult.migration = MigrationOps = { ops: MigrationOp[] }` (required, default
  `{ ops: [] }`); `MigrationOp = { kind, from, to?, scale, detail? }` with `kind ∈
  MIGRATION_KINDS = migration | refugees | diaspora | exodus` and `scale ∈
  MIGRATION_SCALES = small | moderate | large` (`to` is required for every kind except
  `exodus`, which has no destination). Like the hybrid / disasters layers this is
  **turn-transient**: it owns NO `GameState` field (no durable list, no `db.ts` change) — a
  flow that persists is simply re-declared each turn it continues. The DETERMINISTIC
  `MIGRATION_SOURCE_EFFECTS` / `MIGRATION_DESTINATION_EFFECTS` tables
  (`server/abilities/migration.ts`) map each `scale` to signed stat deltas (no hidden
  randomness): the source LOSES population + economy (small −1/−1, moderate −2/−2,
  large −4/−3) and the destination GAINS population + economy (small +1/+1, moderate
  +2/+2, large +3/+3); a `large` influx additionally strains the destination's stability by
  `LARGE_INFLUX_STABILITY_DIP = -2`. Neither side ever moves territory (sole ownership is
  untouched) and none touch borders. Both `from` and `to` resolve by the shared
  `resolveNationRef` (id first, then a case-insensitive unique name): an unknown / ambiguous
  source, a missing / unknown / ambiguous destination, or a **self-flow** (`from` and `to`
  the same nation) drops the WHOLE op (the source is untouched); `exodus` skips the
  destination entirely. The from↔to relation then moves one step toward the positive end of
  the ally/neutral/rival/hostile ladder via the self-contained `shiftRelationTowardPositive`
  (the mirror of the hybrid layer's `shiftRelationTowardHostile`): capped at `ally` for
  `refugees` (hosting refugees builds the strongest goodwill), `neutral` for `migration` /
  `diaspora`, and not at all for `exodus`; a missing relation starts at `neutral` and a
  `war` relation is NEVER touched (the nudge neither fabricates nor escalates a war).
  `applyMigrationOp` (run in the `ABILITIES` loop after territory / wars / economy, before
  markers) applies the source dip, then the destination dip (+ stability strain for `large`),
  clamps both to 0–100, mirrors each to every region the nation owns (`regionStats`), and
  re-derives each nation's aggregate `stats` (the same 0-region / no-entry guards, so a
  0-region nation keeps its directly-mutated value and the effect persists). `payload()` is
  `{}` (turn-transient), so the user-prompt golden (`user.txt`) is unchanged; the system
  prompt gains the field's schema line + constraint bullet (the system goldens were
  re-baselined in v0.42.0). `isMeaningful` is `ops.length > 0`. The stub never proposes a
  migration (`{ ops: [] }`), so e2e (CI, `LLM_STUB=1`) is unaffected and the path is
  unit-tested only (`server/abilities/migration.test.ts`). **Design note:** the Gitea #64
  body sketched a simpler `flows: {type: 'refugees'|'settlers'}` shape with a settler
  re-claim of no-man's-land; the implemented, approved design is this richer four-kind
  nation-to-nation **stat** layer that deliberately never moves territory (a no-man's-land
  re-claim stays the `regionChanges` lever's job).
 - **Sea control — sole control of a fixed set of 12 named sea zones with a deterministic per-turn bonus (v0.43.0, #65).**
  `TurnResult.sea = SeaOps = { control: SeaControlOp[] }` (required, default `{ control: [] }`);
  `SeaControlOp = { zone, by }` where `zone` is one of the 12 fixed sea-zone ids from
  `SEA_ZONES` in `shared/protocol.ts` (`north-atlantic`, `south-atlantic`, `pacific`, `indian`,
  `mediterranean`, `north-sea`, `baltic`, `arctic`, `black-sea`, `gulf-mexico`, `red-sea`,
  `sargasso`) and `by` is a nation ref (id first, then a case-insensitive unique name, via the
  shared `resolveNationRef`; unknown / ambiguous → dropped, never thrown). Like the wars and
  industry layers this is **durable** (unlike the turn-transient hybrid / disasters / migration
  layers): it owns the `GameState.seaZones` field (required, `[]` at creation; a legacy SQLite
  row without the field loads as `[]` — via the generic `ABILITIES` `stateFields` loop in
  `db.ts`, no `db.ts` code change needed). `applySeaControl` (run in the `ABILITIES` loop after
  territory / wars / economy, before markers) upserts the turn's ops into `next.seaZones`:
  per zone (in first-appearance order) a single surviving op sets or replaces the zone's
  controller (replace in place — preserving position — or append); two or more surviving ops
  on the same zone for different resolved nations make the zone **contested** — the higher
  current `stats.military` wins (a tie goes to the earlier-listed op) — deterministic, no
  hidden randomness. The layer **never touches `territory` / `unowned`** — it is fully parallel
  to but independent of land. Every committed turn (including a turn with an empty `control`),
  `applySeaZoneBonuses` grants each existing claim's controller `SEA_ZONE_BONUS = 1` military
  + 1 economy (clamped to 0–100, mirrored to every region the nation owns, then the nation's
  derived `stats` re-derived with the same 0-region / no-entry guards as the economy / migration
  layers, so a 0-region nation keeps its directly-mutated value); a nation controlling several
  zones stacks the bonus; a claim whose nation no longer exists (removed by a merge / split
  this turn) is skipped — the claim is kept, never thrown. `isMeaningful` is
  `control.length > 0`. The system prompt documents the field + constraints (at most 1–2 claims
  per turn, each narrated in `events`); the user payload **always** carries the current
  `seaZones` list (even when empty) — `payload()` → `{ seaZones: ctx.seaZones ?? [] }` — the
  one ability whose `payload()` is not `{}` (the durable list, unlike the turn-transient
  layers). The **stub never** proposes a sea op (`{ control: [] }`), so e2e (CI, `LLM_STUB=1`)
  is unaffected and the path is unit-tested only (`server/abilities/sea.test.ts`).
  **Design note:** the Gitea #65 body sketched a `naval` layer with a free-form `zones`
  array; the implemented, approved design is this richer `sea` layer with a **fixed set of
  12 named zones**, sole-control semantics, contest-by-higher-military, and a durable
  `seaZones` list — a cleaner, more deterministic model that the LLM can reason about without
  inventing zone names each turn.
 - **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
  owning nation (`focusNation(ownerId, {name})` in `App.tsx`, which also records which region was
@@ -2,6 +2,30 @@
 All notable changes to **History** are listed here, newest first.
 ## v0.43.0 — 2026-10-16 12:09
 - **#65: Sea control — a `TurnResult.sea` lever letting the LLM declare sole control over a fixed set of 12 named sea zones (North Atlantic, South Atlantic, Pacific, Indian, Mediterranean, North Sea, Baltic, Arctic, Black Sea, Gulf of Mexico, Red Sea, Sargasso), with a deterministic per-turn +1 military / +1 economy bonus for the controlling nation.** It is a **durable** feature (unlike the turn-transient `hybrid` / `disasters` / `migration` layers): `GameState.seaZones` persists across turns and in SQLite, and the user payload **always** carries the current `seaZones` list (even when empty) so the model knows who controls what. It lands as the **11th ability** of the v0.40.0 modular system, in a new `server/abilities/sea.ts` module, **registered last** in the `ABILITIES` registry (after `migration`). Sea control is fully **parallel to but independent of land**: it never touches `territory` / `unowned`, and moving land never touches a sea zone.
  - **Types (`shared/protocol.ts`).** New `SEA_ZONES` (a frozen array of 12 `{ id, name }` pairs), `SEA_ZONE_IDS` (a `ReadonlySet` of all 12 ids), `isSeaZoneId(id)` (type guard), `seaZoneName(id)` (human-readable name; unknown → raw), `SeaControlOp` (`{ zone; by }`), and `SeaOps` (`{ control: SeaControlOp[] }`); `TurnResult.sea` is **required**, placed between `migration` and `markers`, default `{ control: [] }`. New `SeaZoneClaim` (`{ zone; by }`) in `shared/types.ts`; `GameState.seaZones: SeaZoneClaim[]` is **required** (`[]` at creation; a legacy SQLite row without the field loads as `[]` — additive, never wiped, via the generic `ABILITIES` `stateFields` loop in `db.ts` — no `db.ts` code change needed).
  - **Ability module (`server/abilities/sea.ts`).** `field: 'sea'`; `default()` / `stub()` → a **fresh** `{ control: [] }` each call; `validate` wraps the exported `validateSeaOps` (defensive, never throws — accepts the `{ control: [...] }` object or a bare array; each op needs a valid `zone` (one of the 12 `SEA_ZONE_IDS`) and a non-empty `by` (trimmed, ≤200) — anything else is dropped); `apply` runs `applySeaControl` then `applySeaZoneBonuses`; `schemaLine()` / `constraint()` supply the prompt text; **`payload()` → `{ seaZones: ctx.seaZones ?? [] }` — the one ability that always emits a user-payload key** (the durable list, even when empty — unlike the turn-transient layers whose `payload()` is `{}`); `isMeaningful` = `control.length > 0`; **`stateFields: ['seaZones']`** (the durable `GameState` field, for the `db.ts` legacy-row migration).
  - **Contest semantics (`applySeaControl`).** Each op's `by` is resolved via the shared `resolveNationRef` (id first, then a case-insensitive unique name; unknown / ambiguous → dropped, never thrown). Per zone (in first-appearance order): a single surviving op **sets or replaces** the zone's controller in `GameState.seaZones` (replace in place — preserving the entry's position — or append a new one); two or more surviving ops on the same zone for **different** resolved nations make the zone **contested**: the higher current `stats.military` wins (a tie goes to the op listed earlier in the `control` array) — deterministic, no hidden randomness. The layer **never touches `territory` / `unowned`**.
  - **Per-turn bonus (`applySeaZoneBonuses`).** Every committed turn — **including a turn with an empty `control`** — each existing claim's controller earns `SEA_ZONE_BONUS = 1` military + 1 economy (clamped to 0–100, mirrored to every region the nation owns, then the nation's derived `stats` re-derived with the same 0-region / no-entry guards as the economy / migration layers, so a 0-region nation keeps its directly-mutated value). A nation controlling several zones **stacks** the bonus (one per zone). A claim whose nation no longer exists (removed by a merge / split this turn) is **skipped** — the claim is kept, never thrown.
  - **Registry & prompt.** `sea` is added **last** in `ABILITIES` (existing order untouched); the system prompt gains the `sea` schema line and its constraint bullet ("at most 1–2 claims per turn, each narrated in `events`"); the **user prompt gains `"seaZones": []` as a new last key** (the intentional deviation from the turn-transient layers — the durable list is always emitted). The two committed system-prompt **goldens** are regenerated (each gains exactly the new `sea` schema line + constraint bullet); the **`user.txt` golden gains `"seaZones": []`** as the last key (verified by diff).
  - **Tests.** New `server/abilities/sea.test.ts` (**~40 tests**): the zone-id predicate sets; `validateSeaOps` (shape / leniency / drops / field caps); `applySeaControl` (set / replace-in-place / append / contest by military / tie-break / same-nation dedup / name-resolve / unresolvable drop / ambiguous drop / territory-untouched); `applySeaZoneBonuses` (+1/+1 / clamping / stacking / 0-region direct-dip / stale-controller skip / empty no-op / territory-untouched); and the ability const contract (field, `stateFields`, fresh `default()`/`stub()`, `isMeaningful`, `payload()` incl. `?? []`, `validate` wrapping, `apply` ctx wiring). `registry.test.ts` is updated for the **11-ability** contract (order, distinct fields, `fullDefaultTurn()`, `meaningfulFor`, durable fields, composes 12 / `extended[11]`, re-export pin, user-golden 14th arg). New `db.test.ts` legacy-row test (a pre-v0.43 save without `seaZones` loads with `[]`).
  - **Design note (deviation from the issue body).** The Gitea #65 body sketched a `naval` layer with a free-form `zones` array; the approved design implemented here is the richer `sea` layer with a **fixed set of 12 named zones**, sole-control semantics, contest-by-higher-military, and a durable `seaZones` list — a cleaner, more deterministic model that the LLM can reason about without inventing zone names each turn.
 - **Guarantees.** No client (`src/`) changes, no new runtime deps, `shared/` keeps zero runtime deps, no `@turf`/`@types/geojson` in any `.ts`. All unit tests green (additive); e2e (CI, `LLM_STUB=1`) unaffected (the stub is sea-inert — it never proposes a sea op).
 - **Version** bumped `0.42.0 → 0.43.0`.
 ## v0.42.0 — 2026-10-16 10:12
 - **#64: Migration & refugees — a `TurnResult.migration` lever letting the LLM declare population flows between nations (ordinary migration / refugee flows / a spreading diaspora / an exodus), with a deterministic per-`scale` effect: the source loses a little population and economy, the destination gains a little (a `large` influx also strains its stability), and the from↔to relation is nudged one step toward the positive end of the ladder.** It is a **turn-transient** feature, exactly like the v0.34 `hybrid` and v0.41 `disasters` layers: **no new `GameState` field, no `db.ts` change, no durable list** — the ops are consumed inside `applyTurnResult` and leave nothing behind. It lands as the **10th ability** of the v0.40.0 modular system, in a new `server/abilities/migration.ts` module, **registered last** in the `ABILITIES` registry (after `disasters`).
  - **Types (`shared/protocol.ts`).** New `MigrationKind` (`'migration' | 'refugees' | 'diaspora' | 'exodus'`), `MigrationScale` (`'small' | 'moderate' | 'large'`), `MigrationOp` (`{ kind; from; to?; scale; detail? }` — `to` is required for every kind except `exodus`, which has no destination), and `MigrationOps` (`{ ops: MigrationOp[] }`); `TurnResult.migration` is **required**, placed between `disasters` and `markers`, default `{ ops: [] }`.
  - **Ability module (`server/abilities/migration.ts`).** `field: 'migration'`; `default()` / `stub()` → a **fresh** `{ ops: [] }` each call; `validate` wraps the exported `validateMigrationOps` (defensive, never throws — accepts the `{ ops: [...] }` object or a bare array; each op needs a valid `kind`, a valid `scale`, a non-empty `from` (trimmed, ≤200), and — for every kind except `exodus` — a non-empty `to` (trimmed, ≤200); an optional `detail` (trimmed, ≤300, empty dropped) — anything else is dropped); `apply` runs `applyMigrationOp` per op; `schemaLine()` / `constraint()` supply the prompt text; `payload()` → `{}` (no user-payload keys — both refs resolve from the existing nation ref table); `isMeaningful` = `ops.length > 0`; **no** `stateFields` (turn-transient, no durable `GameState` field).
  - **Deterministic effects (tables, no hidden randomness).** `MIGRATION_SOURCE_EFFECTS` per scale — the source LOSES: small `{population:-1, economy:-1}`, moderate `{population:-2, economy:-2}`, large `{population:-4, economy:-3}`. `MIGRATION_DESTINATION_EFFECTS` per scale — the destination GAINS: small `{population:+1, economy:+1}`, moderate `{population:+2, economy:+2}`, large `{population:+3, economy:+3}`. `LARGE_INFLUX_STABILITY_DIP = -2` — a `large` influx additionally strains the destination's stability by 2. All clamped to 0–100.
  - **Apply semantics (`applyMigrationOp`).** Resolution is drop-first: `from` must resolve to a nation (id first, then a unique name; unknown / ambiguous → drop); for every kind except `exodus` the `to` must resolve to a nation **distinct from** `from` (missing / unknown / ambiguous / self-flow → the **whole op** is dropped, the source untouched). Only then is the source dip applied (all four kinds, including `exodus`); `exodus` then returns (no destination, no nudge). Otherwise the destination gain is applied (plus the `large` stability strain), and the from↔to relation is nudged by the self-contained `shiftRelationTowardPositive` — the mirror of the hybrid layer's `shiftRelationTowardHostile`, but toward `ally` (`POSITIVE_ORDER = ['ally','neutral','rival','hostile']`, cap `ally` for `refugees`, `neutral` for `migration` / `diaspora`, none for `exodus`; a missing relation starts at `neutral`; a `war` relation is **never** touched — the nudge neither fabricates nor escalates a war). Each affected nation's dip is clamped to 0–100, **mirrored to every region it owns** (`regionStats`), and its derived `stats` **re-derived** afterwards (the same 0-region / no-entry guards as hybrid / economy / disasters — a 0-region nation keeps its directly-mutated value and the effect persists). It **never moves territory** (sole ownership is untouched). The **stub never** proposes a migration (`{ ops: [] }`), so e2e (CI, `LLM_STUB=1`) is unaffected and the path is covered by unit tests only.
  - **Registry & prompt.** `migration` is added **last** in `ABILITIES` (existing order untouched); the system prompt gains the `migration` schema line and its constraint bullet ("at most 1–2 per turn, each narrated in `events` as a `social` or `diplomatic` event"); the user prompt is unchanged (`payload()` is `{}`). The two committed system-prompt **goldens** (`system-no-tool.txt`, `system-tool.txt`) are regenerated (each gains exactly the new `migration` schema line + constraint bullet); the **`user.txt` golden stays byte-identical** (no new user-payload keys — verified by checksum).
  - **Tests.** New `server/abilities/migration.test.ts` (**38 tests**): the kind/scale predicate sets; the three effect tables (exact keys / signs / monotonicity); `validateMigrationOps` (shape / leniency / drops / field caps); `shiftRelationTowardPositive` (one-step nudge, caps, war-untouched, missing→neutral, unknown no-op); `applyMigrationOp` (small / moderate / large source & destination dips, the `large` stability strain, name-based resolve, the relation nudge by kind, war-untouched, exodus-only-source, self-flow drop, unknown / ambiguous source & destination drop, 0-region direct-dip persistence, territory-untouched, clamping at 0 and 100); and the ability const contract (field, no `stateFields`, fresh `default()`/`stub()`, `isMeaningful`, `payload() {}`, `validate` wrapping, `apply` ctx wiring). `registry.test.ts` is updated for the **10-ability** contract (order, distinct fields, `fullDefaultTurn()`, `meaningfulFor`, re-export pin); the goldens are regenerated (verified idempotent).
  - **Design note (interpretation of the issue body).** The Gitea #64 body sketched a simpler `flows: { type: 'refugees' | 'settlers' }` shape that included a settler **re-claim of no-man's-land**; the refined, approved design implemented here is the richer `migration.ops` union of **four nation-to-nation population-flow kinds** (migration / refugees / diaspora / exodus) — a purely **stat** layer that **never moves territory** (sole ownership stays untouched; a no-man's-land re-claim is deliberately out of scope, as territory movement remains the `regionChanges` lever's job).
 - **Guarantees.** No client (`src/`) changes, no new runtime deps, `shared/` keeps zero runtime deps, and no `@turf`/`@types/geojson` in any `.ts`. All unit tests green (additive); e2e (CI, `LLM_STUB=1`) unaffected (the stub is migration-inert).
 - **Version** bumped `0.41.0 → 0.42.0`.
 ## v0.41.0 — 2026-10-16 09:07
 - **#63: Disasters & pandemics — a `TurnResult.disasters` lever letting the LLM declare natural/man-made disasters (earthquake / flood / volcanic / wildfire / famine / plague / epidemic) on a nation or a region, with a deterministic stat dip (stability / economy / military).** It is a **turn-transient** feature, exactly like the v0.34 `hybrid` layer: **no new `GameState` field, no `db.ts` change, no durable list** — the ops are consumed inside `applyTurnResult` and leave nothing behind. It lands as the **9th ability** of the v0.40.0 modular system, in a new `server/abilities/disasters.ts` module, **registered last** in the `ABILITIES` registry (after `ideology`, before the loop appends `markers` / `nationOps`).
  - **Types (`shared/protocol.ts`).** New `DisasterType` (`'earthquake' | 'flood' | 'volcanic' | 'wildfire' | 'famine' | 'plague' | 'epidemic'`), `DisasterSeverity` (`'minor' | 'moderate' | 'severe'`), `DisasterEvent` (`{ type; target; severity; detail? }` — `target` is a nation ref **or** a region key), and `DisastersOps` (`{ events: DisasterEvent[] }`); `TurnResult.disasters` is **required**, placed between `ideology` and `markers`, default `{ events: [] }`.
@@ -1,6 +1,6 @@
 {
  "name": "history",
-  "version": "0.41.0",
+  "version": "0.43.0",
  "private": true,
  "type": "module",
  "description": "AI-driven alternate-history simulator — the LLM is the world engine (Pax Historia style).",
@@ -70,6 +70,8 @@ function mkState(
    trades: [],
    embargoes: [],
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
 }
@@ -40,6 +40,8 @@ Respond with ONLY a valid JSON object of exactly this shape. No prose, no commen
  "leaders": {"changes":[{"target":"<nation id or name>","name":"<new leader name>","cause":"<assassination|death|appointed>"}]},
  "ideology": {"changes":[{"target":"<nation id or name>","to":"<new form of government>"}]},
  "disasters": {"events":[{"type":"<earthquake|flood|volcanic|wildfire|famine|plague|epidemic>","target":"<nation id or name, or region key>","severity":"<minor|moderate|severe>","detail":"<short detail>"}]},
  "migration": {"ops":[{"kind":"<migration|refugees|diaspora|exodus>","from":"<nation id or name>","to":"<nation id or name>","scale":"<small|moderate|large>","detail":"<short detail>"}]},
  "sea": {"control":[{"zone":"<seaZoneId>","by":"<nation id or name>"}]},
  "markers": {"add":[{"type":"<city|factory|army|port|capital|fleet|rocket|gathering>","name":"<short name>","regionKey":"<region key>"}],"remove":["<marker id>"]}
 }
@@ -66,6 +68,8 @@ HARD CONSTRAINTS
 - Leaders ("leaders") name each nation's current head of state and change it. Each change is {"target":"<nation id or name>","name":"<new leader name>","cause":"<assassination|death|appointed>"}: "assassination" kills the current leader (a dramatic, destabilizing blow — a −15 stability dip, a "military" event) and is only valid when the target already has a leader; "death" is a natural-causes succession (a quieter −3 dip, a "political" event), also only valid for a nation that has a leader; "appointed" sets (or creates) a leader and is always valid (a neutral 0 effect, a "political" event). Propose at most 1-2 changes per turn and narrate each one in "events". This is the HEAVY leader lever — use the lighter "hybrid" {"type":"assassinate"} op (a −5 stability dip, no leader replacement) for a mere hit on a leader or region without changing who is in charge. The user message's "nations" field lists each nation's current "leader" (omitted when a nation has none).
 - Ideology ("ideology") is each nation's form of government — a free-form label such as "democracy", "fascism", or "military junta" — that can shift through a coup, a revolution, a reform, or a constitutional change. Each change is {"target":"<nation id or name>","to":"<new form of government>"}: the engine sets the nation's ideology, applies a small, deterministic stability dip (−5 — a regime shift always unsettles a nation), and narrates it with a "political" event. It is a third axis, distinct from a takeover (which RENAMES the nation) and from a leader change (who is in charge): the nation keeps its id, name, territory, relations, and leader — only its form of government and its stability move. Similar forms of government are a SOFT, prompt-level compatibility nudge only (nations with alike ideologies tend to ally and trade; very opposed ones tend to clash) — there is no engine gate behind it. Propose at most 1-2 changes per turn and narrate each one in "events". The user message's "nations" field lists each nation's current "ideology" (omitted when a nation has none).
 - Disasters & pandemics ("disasters.events") are natural and man-made catastrophes — earthquakes, floods, volcanic eruptions, wildfires, famines, plagues, and epidemics — that hit a nation or a single region this turn. Each event names a "target" (a nation id / name, or a region key that hits that region's SOLE owner — a region with 0 or 2+ owners can't be hit) and a "severity" (minor / moderate / severe); the engine applies a small, DETERMINISTIC stat dip from the (type, severity) table (a severe plague is the hardest hit; none of them touch population, and none move borders — sole ownership is untouched). There is NO memory of past disasters (the layer is turn-transient): a plague or epidemic that persists is simply RE-DECLARED each turn it continues, with a fresh "severity". Propose at most 1-2 events per turn and narrate each one in "events" (a "disaster" event).
 - Migration & refugees ("migration.ops") are people moving between nations this turn: a "kind" ("migration", "refugees", "diaspora", or "exodus"), a "from" (the source nation — id or name), a "to" (the destination nation — required for every kind except "exodus", which has no destination), and a "scale" (small / moderate / large). The engine applies a DETERMINISTIC effect (no hidden randomness): the source LOSES a small amount of population and economy, the destination GAINS a small amount of population and economy (a "large" influx additionally strains the destination's stability by 2), and the from↔to relation moves one step toward the positive end of the ally/neutral/rival/hostile ladder — capped at "ally" for "refugees" (hosting refugees builds the strongest goodwill), capped at "neutral" for "migration"/"diaspora" (milder ties), and not at all for "exodus"; the nudge never creates or escalates a "war" (a warring pair is left untouched). The layer is turn-transient (no memory): a continuing flow is simply RE-DECLARED each turn it persists. It never moves borders — sole ownership is untouched. Propose at most 1-2 per turn and narrate each one in "events" (a "social" or "diplomatic" event).
 - Sea control ("sea") is the naval layer, fully parallel to but INDEPENDENT of land: each of the 12 fixed sea zones — "north-atlantic" (North Atlantic), "south-atlantic" (South Atlantic), "pacific" (Pacific Ocean), "indian" (Indian Ocean), "mediterranean" (Mediterranean Sea), "north-sea" (North Sea), "baltic" (Baltic Sea), "arctic" (Arctic Ocean), "black-sea" (Black Sea), "gulf-mexico" (Gulf of Mexico), "red-sea" (Red Sea), "sargasso" (Sargasso Sea) — is under the SOLE control of at most one nation. A control op ({"zone":"<id>","by":"<nation>"}) sets or replaces that zone's controller (the user message's "seaZones" field lists who controls what now); if two or more ops this turn claim the SAME zone for DIFFERENT nations, the zone is CONTESTED and the higher current "military" wins (a tie goes to the earlier-listed op). Every committed turn each zone's controller earns a small deterministic +1 military and +1 economy. Sea control NEVER moves land (no territory changes) — it is a parallel track. Propose at most 1-2 claims per turn and narrate each one in "events" (a "military" or "diplomatic" event).
 - 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.
@@ -40,6 +40,8 @@ You have a getNeighbours tool: given region keys it returns the region keys that
  "leaders": {"changes":[{"target":"<nation id or name>","name":"<new leader name>","cause":"<assassination|death|appointed>"}]},
  "ideology": {"changes":[{"target":"<nation id or name>","to":"<new form of government>"}]},
  "disasters": {"events":[{"type":"<earthquake|flood|volcanic|wildfire|famine|plague|epidemic>","target":"<nation id or name, or region key>","severity":"<minor|moderate|severe>","detail":"<short detail>"}]},
  "migration": {"ops":[{"kind":"<migration|refugees|diaspora|exodus>","from":"<nation id or name>","to":"<nation id or name>","scale":"<small|moderate|large>","detail":"<short detail>"}]},
  "sea": {"control":[{"zone":"<seaZoneId>","by":"<nation id or name>"}]},
  "markers": {"add":[{"type":"<city|factory|army|port|capital|fleet|rocket|gathering>","name":"<short name>","regionKey":"<region key>"}],"remove":["<marker id>"]}
 }
@@ -66,6 +68,8 @@ HARD CONSTRAINTS
 - Leaders ("leaders") name each nation's current head of state and change it. Each change is {"target":"<nation id or name>","name":"<new leader name>","cause":"<assassination|death|appointed>"}: "assassination" kills the current leader (a dramatic, destabilizing blow — a −15 stability dip, a "military" event) and is only valid when the target already has a leader; "death" is a natural-causes succession (a quieter −3 dip, a "political" event), also only valid for a nation that has a leader; "appointed" sets (or creates) a leader and is always valid (a neutral 0 effect, a "political" event). Propose at most 1-2 changes per turn and narrate each one in "events". This is the HEAVY leader lever — use the lighter "hybrid" {"type":"assassinate"} op (a −5 stability dip, no leader replacement) for a mere hit on a leader or region without changing who is in charge. The user message's "nations" field lists each nation's current "leader" (omitted when a nation has none).
 - Ideology ("ideology") is each nation's form of government — a free-form label such as "democracy", "fascism", or "military junta" — that can shift through a coup, a revolution, a reform, or a constitutional change. Each change is {"target":"<nation id or name>","to":"<new form of government>"}: the engine sets the nation's ideology, applies a small, deterministic stability dip (−5 — a regime shift always unsettles a nation), and narrates it with a "political" event. It is a third axis, distinct from a takeover (which RENAMES the nation) and from a leader change (who is in charge): the nation keeps its id, name, territory, relations, and leader — only its form of government and its stability move. Similar forms of government are a SOFT, prompt-level compatibility nudge only (nations with alike ideologies tend to ally and trade; very opposed ones tend to clash) — there is no engine gate behind it. Propose at most 1-2 changes per turn and narrate each one in "events". The user message's "nations" field lists each nation's current "ideology" (omitted when a nation has none).
 - Disasters & pandemics ("disasters.events") are natural and man-made catastrophes — earthquakes, floods, volcanic eruptions, wildfires, famines, plagues, and epidemics — that hit a nation or a single region this turn. Each event names a "target" (a nation id / name, or a region key that hits that region's SOLE owner — a region with 0 or 2+ owners can't be hit) and a "severity" (minor / moderate / severe); the engine applies a small, DETERMINISTIC stat dip from the (type, severity) table (a severe plague is the hardest hit; none of them touch population, and none move borders — sole ownership is untouched). There is NO memory of past disasters (the layer is turn-transient): a plague or epidemic that persists is simply RE-DECLARED each turn it continues, with a fresh "severity". Propose at most 1-2 events per turn and narrate each one in "events" (a "disaster" event).
 - Migration & refugees ("migration.ops") are people moving between nations this turn: a "kind" ("migration", "refugees", "diaspora", or "exodus"), a "from" (the source nation — id or name), a "to" (the destination nation — required for every kind except "exodus", which has no destination), and a "scale" (small / moderate / large). The engine applies a DETERMINISTIC effect (no hidden randomness): the source LOSES a small amount of population and economy, the destination GAINS a small amount of population and economy (a "large" influx additionally strains the destination's stability by 2), and the from↔to relation moves one step toward the positive end of the ally/neutral/rival/hostile ladder — capped at "ally" for "refugees" (hosting refugees builds the strongest goodwill), capped at "neutral" for "migration"/"diaspora" (milder ties), and not at all for "exodus"; the nudge never creates or escalates a "war" (a warring pair is left untouched). The layer is turn-transient (no memory): a continuing flow is simply RE-DECLARED each turn it persists. It never moves borders — sole ownership is untouched. Propose at most 1-2 per turn and narrate each one in "events" (a "social" or "diplomatic" event).
 - Sea control ("sea") is the naval layer, fully parallel to but INDEPENDENT of land: each of the 12 fixed sea zones — "north-atlantic" (North Atlantic), "south-atlantic" (South Atlantic), "pacific" (Pacific Ocean), "indian" (Indian Ocean), "mediterranean" (Mediterranean Sea), "north-sea" (North Sea), "baltic" (Baltic Sea), "arctic" (Arctic Ocean), "black-sea" (Black Sea), "gulf-mexico" (Gulf of Mexico), "red-sea" (Red Sea), "sargasso" (Sargasso Sea) — is under the SOLE control of at most one nation. A control op ({"zone":"<id>","by":"<nation>"}) sets or replaces that zone's controller (the user message's "seaZones" field lists who controls what now); if two or more ops this turn claim the SAME zone for DIFFERENT nations, the zone is CONTESTED and the higher current "military" wins (a tie goes to the earlier-listed op). Every committed turn each zone's controller earns a small deterministic +1 military and +1 economy. Sea control NEVER moves land (no territory changes) — it is a parallel track. Propose at most 1-2 claims per turn and narrate each one in "events" (a "military" or "diplomatic" event).
 - 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.
@@ -205,5 +205,6 @@
      "regionKey": "a-r1",
      "type": "industry"
    }
-  ]
+  ],
  "seaZones": []
 }
@@ -1,8 +1,8 @@
 // The ordered LLM-ability registry.
 //
-// `ABILITIES` is the single source of truth for the 9 per-feature LLM abilities.
+// `ABILITIES` is the single source of truth for the 11 per-feature LLM abilities.
 // The engine iterates it in this order:
-//   takeovers → wars → hybrid → economy → industry → nuclear → leaders → ideology → disasters
+//   takeovers → wars → hybrid → economy → industry → nuclear → leaders → ideology → disasters → migration → sea
 // for (a) the system-prompt schema lines + constraint bullets, (b) the per-ability
 // validate calls inside validateTurnResult, (c) the payload fields in buildUserPrompt,
 // (d) the ordered apply block inside applyTurnResult, (e) the isMeaningful check,
@@ -23,13 +23,17 @@ import { nuclear } from './nuclear';
 import { leaders } from './leaders';
 import { ideology } from './ideology';
 import { disasters } from './disasters';
 import { migration } from './migration';
 import { sea } from './sea';
 import type { Ability, AbilityField } from './types';
 /**
- * The 9 per-feature LLM abilities in their canonical apply order.
+ * The 11 per-feature LLM abilities in their canonical apply order.
 * The order matters: it determines the order of the schema lines in the
 * system prompt, the order of the validate calls, the order of the apply
- * steps, and the order of the payload fields in the user prompt.
+ * steps, and the order of the payload fields in the user prompt. New
 * abilities are APPENDED last — never reorder existing entries (their order
 * is pinned by the goldens and the stub's byte-identical output).
 */
 export const ABILITIES: readonly Ability<AbilityField>[] = [
  takeovers,
@@ -41,6 +45,8 @@ export const ABILITIES: readonly Ability<AbilityField>[] = [
  leaders,
  ideology,
  disasters,
  migration,
  sea,
 ];
 // ── type re-exports ────────────────────────────────────────────────────────────
@@ -139,3 +145,31 @@ export {
  DISASTER_SEVERITIES,
  DISASTER_EFFECTS,
 } from './disasters';
 // ── migration ────────────────────────────────────────────────────────────────
 export {
  validateMigrationOps,
  applyMigrationOp,
  shiftRelationTowardPositive,
  isMigrationKind,
  isMigrationScale,
  MIGRATION_KINDS,
  MIGRATION_SCALES,
  MIGRATION_SOURCE_EFFECTS,
  MIGRATION_DESTINATION_EFFECTS,
  LARGE_INFLUX_STABILITY_DIP,
 } from './migration';
 // ── sea ──────────────────────────────────────────────────────────────────────
 export {
  validateSeaOps,
  applySeaControl,
  applySeaZoneBonuses,
  SEA_ZONE_BONUS,
  SEA_ZONES,
  SEA_ZONE_IDS,
  isSeaZoneId,
  seaZoneName,
 } from './sea';
@@ -0,0 +1,572 @@
 // Unit tests for the MIGRATION & REFUGEES ability (v0.42.0, #64) — the
 // modular, turn-transient LLM-ability that moves population between nations:
 // the source loses a small amount of population and economy, the destination
 // gains a small amount (a `large` influx also strains the destination's
 // stability), each side's aggregate stats are re-derived, and the from↔to
 // relation is nudged one step toward the positive end of the ladder (capped by
 // kind; a war is never touched). This is the ability's own test file (the
 // registry's cross-cutting guarantees — order, distinct fields, the
 // system/user goldens — are covered by ./registry.test.ts). The stub never
 // proposes a migration, so the apply path is exercised here, not by the e2e
 // suite.
 import { describe, expect, it } from 'vitest';
 import {
  LARGE_INFLUX_STABILITY_DIP,
  MIGRATION_DESTINATION_EFFECTS,
  MIGRATION_KINDS,
  MIGRATION_SCALES,
  MIGRATION_SOURCE_EFFECTS,
  applyMigrationOp,
  isMigrationKind,
  isMigrationScale,
  migration,
  shiftRelationTowardPositive,
  validateMigrationOps,
 } from './migration';
 import type { MigrationScale } from '../../shared/protocol';
 import type { GameState, Nation, NationStats, RelationStatus, RegionStats } from '../../shared/types';
 // ---------------------------------------------------------------------------
 // Fixture helpers
 // ---------------------------------------------------------------------------
 /** Build a NationStats from the four canonical indices (military, economy, stability, population). */
 function NS(military: number, economy: number, stability: number, population: number): NationStats {
  return { military, economy, stability, population };
 }
 /** Build a RegionStats from the four canonical indices. */
 function RS(military: number, economy: number, stability: number, population: number): RegionStats {
  return { military, economy, stability, population };
 }
 /** A minimal nation: the given id/name/stats/region-key territory, given relations. */
 function mkNation(
  id: string,
  name: string,
  stats: NationStats,
  territory: string[],
  relations: Record<string, RelationStatus> = {},
 ): Nation {
  return { id, name, type: 'major', stats, territory, relations };
 }
 /**
 * A minimal GameState carrying the given nations (keyed by id) and per-region
 * stats. Every other required field is at its fresh-game baseline, so a test
 * can focus purely on the migration effect.
 */
 function mkState(
  nations: Record<string, Nation>,
  regionStats: Record<string, RegionStats>,
 ): GameState {
  return {
    id: 'g1',
    presetId: 'test',
    presetTitle: 'Test',
    playerNationId: Object.keys(nations)[0] ?? 'uk',
    turn: 1,
    date: '1939-09-01',
    nations,
    events: [],
    pending: [],
    version: 1,
    unowned: [],
    pendingNationOps: [],
    markers: [],
    regionStats,
    wars: [],
    trades: [],
    embargoes: [],
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
 }
 // ---------------------------------------------------------------------------
 // Kind / scale constants + predicates
 // ---------------------------------------------------------------------------
 describe('MIGRATION_KINDS / MIGRATION_SCALES', () => {
  it('exposes exactly the four kinds and three scales', () => {
    expect([...MIGRATION_KINDS]).toEqual(['migration', 'refugees', 'diaspora', 'exodus']);
    expect([...MIGRATION_SCALES]).toEqual(['small', 'moderate', 'large']);
  });
 });
 describe('isMigrationKind / isMigrationScale', () => {
  it('accepts each known kind and rejects unknown / non-strings', () => {
    for (const k of MIGRATION_KINDS) expect(isMigrationKind(k)).toBe(true);
    expect(isMigrationKind('immigration')).toBe(false);
    expect(isMigrationKind(42)).toBe(false);
    expect(isMigrationKind(undefined)).toBe(false);
  });
  it('accepts each known scale and rejects unknown / non-strings', () => {
    for (const s of MIGRATION_SCALES) expect(isMigrationScale(s)).toBe(true);
    expect(isMigrationScale('massive')).toBe(false);
    expect(isMigrationScale(42)).toBe(false);
  });
 });
 // ---------------------------------------------------------------------------
 // Effect tables
 // ---------------------------------------------------------------------------
 describe('MIGRATION_SOURCE_EFFECTS / MIGRATION_DESTINATION_EFFECTS', () => {
  it('every source scale dips exactly population and economy (both negative)', () => {
    for (const s of MIGRATION_SCALES) {
      const dips = MIGRATION_SOURCE_EFFECTS[s];
      expect(Object.keys(dips).sort()).toEqual(['economy', 'population']);
      expect(dips.population).toBeLessThan(0);
      expect(dips.economy).toBeLessThan(0);
    }
  });
  it('every destination scale gains exactly population and economy (both positive)', () => {
    for (const s of MIGRATION_SCALES) {
      const gains = MIGRATION_DESTINATION_EFFECTS[s];
      expect(Object.keys(gains).sort()).toEqual(['economy', 'population']);
      expect(gains.population).toBeGreaterThan(0);
      expect(gains.economy).toBeGreaterThan(0);
    }
  });
  it('source loses and destination gains monotonically with scale', () => {
    const [small, moderate, large] = MIGRATION_SCALES;
    const srcPop = (s: MigrationScale) => MIGRATION_SOURCE_EFFECTS[s].population!;
    const dstPop = (s: MigrationScale) => MIGRATION_DESTINATION_EFFECTS[s].population!;
    // A larger scale means the source LOSES more: the (negative) dip grows more
    // negative as the scale grows, i.e. small > moderate > large.
    expect(srcPop(small)).toBeGreaterThan(srcPop(moderate));
    expect(srcPop(moderate)).toBeGreaterThan(srcPop(large));
    // A larger scale means the destination GAINS more: the (positive) gain
    // grows larger as the scale grows, i.e. small < moderate < large.
    expect(dstPop(small)).toBeLessThan(dstPop(moderate));
    expect(dstPop(moderate)).toBeLessThan(dstPop(large));
  });
  it('the large-influx stability strain is a small negative dip', () => {
    expect(LARGE_INFLUX_STABILITY_DIP).toBeLessThan(0);
  });
 });
 // ---------------------------------------------------------------------------
 // validateMigrationOps
 // ---------------------------------------------------------------------------
 describe('validateMigrationOps', () => {
  it('accepts the { ops: [...] } object shape and a bare array', () => {
    const op = { kind: 'migration', from: 'a', to: 'b', scale: 'small' };
    expect(validateMigrationOps({ ops: [op] })).toEqual([op]);
    expect(validateMigrationOps([op])).toEqual([op]);
  });
  it('drops an op with an unknown / missing kind', () => {
    expect(validateMigrationOps([{ kind: 'tsunami', from: 'a', to: 'b', scale: 'small' }])).toEqual(
      [],
    );
    expect(
      validateMigrationOps([
        { from: 'a', to: 'b', scale: 'small' },
        { kind: 'migration', from: 'a', to: 'b', scale: 'small' },
      ]),
    ).toEqual([{ kind: 'migration', from: 'a', to: 'b', scale: 'small' }]);
  });
  it('drops an op with an unknown / missing scale', () => {
    expect(validateMigrationOps([{ kind: 'migration', from: 'a', to: 'b', scale: 'massive' }])).toEqual(
      [],
    );
    expect(validateMigrationOps([{ kind: 'migration', from: 'a', to: 'b' }])).toEqual([]);
  });
  it('drops an op with an empty / missing from (the source)', () => {
    expect(validateMigrationOps([{ kind: 'migration', from: '', to: 'b', scale: 'small' }])).toEqual(
      [],
    );
    expect(validateMigrationOps([{ kind: 'migration', to: 'b', scale: 'small' }])).toEqual([]);
  });
  it('requires a non-empty `to` for every kind except exodus', () => {
    // non-exodus kind missing `to`: dropped
    expect(validateMigrationOps([{ kind: 'migration', from: 'a', scale: 'small' }])).toEqual([]);
    expect(validateMigrationOps([{ kind: 'refugees', from: 'a', scale: 'small' }])).toEqual([]);
    // exodus without a `to`: kept (an exodus has no destination)
    expect(validateMigrationOps([{ kind: 'exodus', from: 'a', scale: 'small' }])).toEqual([
      { kind: 'exodus', from: 'a', scale: 'small' },
    ]);
  });
  it('caps `from` / `to` at 200 chars and `detail` at 300, dropping empty detail', () => {
    const longFrom = 'f'.repeat(500);
    const longDetail = 'd'.repeat(500);
    const out = validateMigrationOps([
      { kind: 'migration', from: longFrom, to: 'b', scale: 'small', detail: longDetail },
    ]);
    expect(out).toHaveLength(1);
    expect(out[0].from).toHaveLength(200);
    expect(out[0].detail).toHaveLength(300);
  });
  it('a missing / malformed top-level value yields an empty list', () => {
    expect(validateMigrationOps(undefined)).toEqual([]);
    expect(validateMigrationOps(null)).toEqual([]);
    expect(validateMigrationOps('nope')).toEqual([]);
    expect(validateMigrationOps({ ops: 'nope' })).toEqual([]);
    expect(validateMigrationOps([{ kind: 'migration' }])).toEqual([]);
  });
 });
 // ---------------------------------------------------------------------------
 // shiftRelationTowardPositive
 // ---------------------------------------------------------------------------
 describe('shiftRelationTowardPositive', () => {
  function pair(rel: Record<string, RelationStatus>): GameState {
    return mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1'], rel),
        b2: mkNation('b2', 'Bravo', NS(50, 50, 50, 50), ['b-r1'], rel),
      },
      { 'a-r1': RS(50, 50, 50, 50), 'b-r1': RS(50, 50, 50, 50) },
    );
  }
  it('nudges a neutral pair one step toward positive, symmetrically', () => {
    const s = pair({ b2: 'neutral', a1: 'neutral' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('ally');
    expect(s.nations.b2.relations.a1).toBe('ally');
  });
  it('never moves past the cap (migration/diaspora cap at neutral)', () => {
    // hostile → rival (one step toward positive, still below the neutral cap)
    let s = pair({ b2: 'hostile', a1: 'hostile' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'neutral');
    expect(s.nations.a1.relations.b2).toBe('rival');
    // rival → neutral (reaches the cap)
    s = pair({ b2: 'rival', a1: 'rival' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'neutral');
    expect(s.nations.a1.relations.b2).toBe('neutral');
    // neutral → stays neutral (at the cap)
    s = pair({ b2: 'neutral', a1: 'neutral' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'neutral');
    expect(s.nations.a1.relations.b2).toBe('neutral');
    // ally → stays ally (more positive than the cap)
    s = pair({ b2: 'ally', a1: 'ally' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'neutral');
    expect(s.nations.a1.relations.b2).toBe('ally');
  });
  it('refugees can nudge all the way to ally (cap ally)', () => {
    let s = pair({ b2: 'hostile', a1: 'hostile' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('rival');
    s = pair({ b2: 'rival', a1: 'rival' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('neutral');
    s = pair({ b2: 'neutral', a1: 'neutral' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('ally');
    // already ally: no change
    s = pair({ b2: 'ally', a1: 'ally' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('ally');
  });
  it('a missing relation starts at neutral and nudges toward the cap', () => {
    const s = pair({});
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('ally');
    expect(s.nations.b2.relations.a1).toBe('ally');
  });
  it('never touches a war relation', () => {
    const s = pair({ b2: 'war', a1: 'war' });
    shiftRelationTowardPositive(s, 'a1', 'b2', 'ally');
    expect(s.nations.a1.relations.b2).toBe('war');
    expect(s.nations.b2.relations.a1).toBe('war');
  });
  it('is a no-op for an unknown nation id or an unknown cap', () => {
    const s = pair({ b2: 'hostile', a1: 'hostile' });
    shiftRelationTowardPositive(s, 'a1', 'zzz', 'ally'); // zzz absent
    expect(s.nations.a1.relations.b2).toBe('hostile');
    shiftRelationTowardPositive(s, 'a1', 'b2', 'nope' as RelationStatus); // bad cap
    expect(s.nations.a1.relations.b2).toBe('hostile');
  });
 });
 // ---------------------------------------------------------------------------
 // applyMigrationOp
 // ---------------------------------------------------------------------------
 describe('applyMigrationOp', () => {
  it('a small migration: source loses pop+eco, destination gains pop+eco, relation unchanged (neutral→neutral)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'migration', from: 'a1', to: 'b2', scale: 'small' });
    // source: economy 70→69, population 50→49 (re-derived from its single region)
    expect(state.nations.a1.stats).toEqual(NS(80, 69, 60, 49));
    // destination: economy 30→31, population 60→61
    expect(state.nations.b2.stats).toEqual(NS(40, 31, 50, 61));
    // both regions mirrored
    expect(state.regionStats['a-r1']).toEqual(RS(80, 69, 60, 49));
    expect(state.regionStats['b-r1']).toEqual(RS(40, 31, 50, 61));
    // a neutral pair is already at the neutral cap: no relation change
    expect(state.nations.a1.relations.b2 ?? 'neutral').toBe('neutral');
    expect(state.nations.b2.relations.a1 ?? 'neutral').toBe('neutral');
  });
  it('resolves `from` / `to` by name (not just id)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'migration', from: 'Alpha', to: 'Bravo', scale: 'moderate' });
    // moderate: source pop -2 / eco -2; destination pop +2 / eco +2
    expect(state.nations.a1.stats).toEqual(NS(80, 68, 60, 48));
    expect(state.nations.b2.stats).toEqual(NS(40, 32, 50, 62));
  });
  it('a large influx strains the destination stability by 2', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'refugees', from: 'a1', to: 'b2', scale: 'large' });
    // destination: eco 30→33, pop 60→63, stability 50→48 (large influx strain)
    expect(state.nations.b2.stats).toEqual(NS(40, 33, 48, 63));
    expect(state.regionStats['b-r1']).toEqual(RS(40, 33, 48, 63));
    // source: eco 70→67, pop 50→46
    expect(state.nations.a1.stats).toEqual(NS(80, 67, 60, 46));
  });
  it('a refugees flow nudges the relation toward ally (cap ally); migration/diaspora stop at neutral', () => {
    const mk = (rel: RelationStatus) =>
      mkState(
        {
          a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1'], { b2: rel }),
          b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1'], { a1: rel }),
        },
        { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
      );
    // refugees: hostile → rival
    let s = mk('hostile');
    applyMigrationOp(s, { kind: 'refugees', from: 'a1', to: 'b2', scale: 'small' });
    expect(s.nations.a1.relations.b2).toBe('rival');
    // migration: hostile → rival (capped at neutral, one step only)
    s = mk('hostile');
    applyMigrationOp(s, { kind: 'migration', from: 'a1', to: 'b2', scale: 'small' });
    expect(s.nations.a1.relations.b2).toBe('rival');
    // migration: rival → neutral (reaches cap)
    s = mk('rival');
    applyMigrationOp(s, { kind: 'diaspora', from: 'a1', to: 'b2', scale: 'small' });
    expect(s.nations.a1.relations.b2).toBe('neutral');
    // refugees: neutral → ally
    s = mk('neutral');
    applyMigrationOp(s, { kind: 'refugees', from: 'a1', to: 'b2', scale: 'small' });
    expect(s.nations.a1.relations.b2).toBe('ally');
  });
  it('never nudges a warring pair (a war is left untouched)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1'], { b2: 'war' }),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1'], { a1: 'war' }),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'refugees', from: 'a1', to: 'b2', scale: 'large' });
    expect(state.nations.a1.relations.b2).toBe('war');
    expect(state.nations.b2.relations.a1).toBe('war');
    // the stat effects still apply (a war does not block population movement)
    expect(state.nations.a1.stats).toEqual(NS(80, 67, 60, 46));
    expect(state.nations.b2.stats).toEqual(NS(40, 33, 48, 63));
  });
  it('an exodus only affects the source: no destination, no relation nudge', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1'], { b2: 'rival' }),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1'], { a1: 'rival' }),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'exodus', from: 'a1', scale: 'small' });
    // source dips
    expect(state.nations.a1.stats).toEqual(NS(80, 69, 60, 49));
    // destination untouched
    expect(state.nations.b2.stats).toEqual(NS(40, 30, 50, 60));
    expect(state.regionStats['b-r1']).toEqual(RS(40, 30, 50, 60));
    // no relation nudge
    expect(state.nations.a1.relations.b2).toBe('rival');
  });
  it('a self-flow (from === to) is dropped entirely', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
    );
    applyMigrationOp(state, { kind: 'migration', from: 'a1', to: 'a1', scale: 'large' });
    // no change at all
    expect(state.nations.a1.stats).toEqual(NS(80, 70, 60, 50));
    expect(state.regionStats['a-r1']).toEqual(RS(80, 70, 60, 50));
  });
  it('an unknown or ambiguous source / destination drops the op', () => {
    const base = () =>
      mkState(
        {
          a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
          b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
        },
        { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
      );
    // unknown source
    let s = base();
    applyMigrationOp(s, { kind: 'migration', from: 'zzz', to: 'b2', scale: 'small' });
    expect(s.nations.b2.stats).toEqual(NS(40, 30, 50, 60));
    // unknown destination
    s = base();
    applyMigrationOp(s, { kind: 'migration', from: 'a1', to: 'zzz', scale: 'small' });
    expect(s.nations.a1.stats).toEqual(NS(80, 70, 60, 50));
    // ambiguous source (two nations share the name)
    const amb = mkState(
      {
        a1: mkNation('a1', 'Twin', NS(80, 70, 60, 50), ['a-r1']),
        a2: mkNation('a2', 'Twin', NS(20, 20, 20, 20), ['a-r2']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'a-r2': RS(20, 20, 20, 20), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(amb, { kind: 'migration', from: 'Twin', to: 'Bravo', scale: 'small' });
    expect(amb.nations.b2.stats).toEqual(NS(40, 30, 50, 60));
  });
  it('a 0-region nation keeps its directly-mutated stats (no re-derive)', () => {
    const state = mkState(
      {
        // a1 owns no regions — its stats are maintained directly, not derived
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), []),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'migration', from: 'a1', to: 'b2', scale: 'moderate' });
    // source (0 regions) keeps the direct dip: eco 70→68, pop 50→48
    expect(state.nations.a1.stats).toEqual(NS(80, 68, 60, 48));
    // destination re-derived from its region
    expect(state.nations.b2.stats).toEqual(NS(40, 32, 50, 62));
  });
  it('never moves territory (sole ownership untouched)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    applyMigrationOp(state, { kind: 'refugees', from: 'a1', to: 'b2', scale: 'large' });
    expect(state.nations.a1.territory).toEqual(['a-r1']);
    expect(state.nations.b2.territory).toEqual(['b-r1']);
  });
  it('clamps affected stats to 0 and 100 (a source at the floor, a destination at the ceiling)', () => {
    const state = mkState(
      {
        // a1 at the population / economy floor
        a1: mkNation('a1', 'Alpha', NS(5, 3, 50, 1), ['a-r1']),
        // b2 near the ceiling: a large gain (+3) pushes it past 100
        b2: mkNation('b2', 'Bravo', NS(90, 98, 50, 98), ['b-r1']),
      },
      { 'a-r1': RS(5, 3, 50, 1), 'b-r1': RS(90, 98, 50, 98) },
    );
    applyMigrationOp(state, { kind: 'migration', from: 'a1', to: 'b2', scale: 'large' });
    // source clamps at 0 (pop 1-4→0, eco 3-3→0)
    expect(state.nations.a1.stats.population).toBe(0);
    expect(state.nations.a1.stats.economy).toBe(0);
    // destination gains but clamps at 100 (pop 98+3→100, eco 98+3→100)
    expect(state.nations.b2.stats.population).toBe(100);
    expect(state.nations.b2.stats.economy).toBe(100);
  });
 });
 // ---------------------------------------------------------------------------
 // The Ability object contract
 // ---------------------------------------------------------------------------
 describe('migration ability', () => {
  it('owns the "migration" field; default() is a fresh empty { ops: [] }', () => {
    expect(migration.field).toBe('migration');
    expect(migration.default()).toEqual({ ops: [] });
    expect(migration.default()).not.toBe(migration.default());
  });
  it('default() is not meaningful; a populated value is', () => {
    expect(migration.isMeaningful(migration.default())).toBe(false);
    expect(
      migration.isMeaningful({ ops: [{ kind: 'exodus', from: 'a1', scale: 'small' }] }),
    ).toBe(true);
  });
  it('validate() wraps the bare-list validator into the { ops } shape', () => {
    expect(
      migration.validate([{ kind: 'migration', from: 'a1', to: 'b2', scale: 'small' }]),
    ).toEqual({ ops: [{ kind: 'migration', from: 'a1', to: 'b2', scale: 'small' }] });
    expect(migration.validate(undefined)).toEqual({ ops: [] });
  });
  it('the stub value equals default() (the stub never proposes a migration)', () => {
    expect(migration.stub()).toEqual({ ops: [] });
  });
  it('payload() is always empty (turn-transient — no durable state to show)', () => {
    expect(migration.payload({} as never)).toEqual({});
  });
  it('stateFields is undefined (the layer owns no durable GameState field)', () => {
    expect(migration.stateFields).toBeUndefined();
  });
  it('apply() runs each validated op against the world (no throw on a bad ref)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(40, 30, 50, 60), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(40, 30, 50, 60) },
    );
    const ctx = { previous: state, actingTurn: state.turn };
    migration.apply(
      state,
      {
        ops: [
          { kind: 'migration', from: 'a1', to: 'b2', scale: 'small' },
          // an unknown source — must be dropped, not throw
          { kind: 'refugees', from: 'ghost', to: 'b2', scale: 'small' },
        ],
      },
      ctx,
    );
    expect(state.nations.a1.stats).toEqual(NS(80, 69, 60, 49));
    expect(state.nations.b2.stats).toEqual(NS(40, 31, 50, 61));
  });
 });
@@ -0,0 +1,325 @@
 // The MIGRATION & REFUGEES ability (v0.42.0, #64) as a modular LLM-ability
 // (v0.40.0, #67). People moving between nations each turn: ordinary migration,
 // refugee flows (fleeing a war or disaster), a spreading diaspora, and an
 // exodus (people leaving with no destination). Unlike most other abilities this
 // one is **turn-transient**: it owns NO `GameState` field (no durable list, no
 // `db.ts` change) — exactly like the hybrid and disasters layers. Each op
 // carries a `kind`, a source `from` (the nation people leave), a destination
 // `to` (required for every kind except `exodus`), and a `scale` (small /
 // moderate / large). The engine applies a DETERMINISTIC effect chosen from the
 // per-`scale` tables below (no hidden randomness — the LLM chooses the kind and
 // scale, the tables decide the magnitude): the source LOSES a small amount of
 // population and economy, the destination GAINS a small amount of population and
 // economy (a `large` influx additionally strains the destination's stability),
 // both clamped to 0–100, mirrored to each side's regions (`regionStats`), and
 // each side's derived `stats` re-derived afterwards (the same 0-region /
 // no-entry guards as hybrid / economy / disasters, so a 0-region nation keeps
 // its directly-mutated value and the effect persists to the next turn). The
 // from↔to relation then moves one step toward the positive end of the
 // ally/neutral/rival/hostile ladder (`shiftRelationTowardPositive`) — capped at
 // `ally` for `refugees` (hosting refugees builds the strongest goodwill),
 // `neutral` for `migration` / `diaspora` (milder ties), and not at all for
 // `exodus`; a `war` relation is never touched (the nudge neither fabricates nor
 // escalates a war). Both `from` and `to` are resolved by the shared
 // `resolveNationRef` (id first, then a case-insensitive unique name); an
 // unknown / ambiguous ref, a missing `to` (for a non-`exodus` kind), or a
 // self-flow (`from` and `to` the same nation) drops the whole op. It never
 // moves territory (sole ownership is untouched).
 import { clampStat, deriveNationStats } from '../../shared/protocol';
 import type { MigrationOp, MigrationScale, MigrationKind } from '../../shared/protocol';
 import type { GameState, Nation, RelationStatus, StatKey } from '../../shared/types';
 import { resolveNationRef, str } from './shared';
 import type { Ability } from './types';
 /** The four kinds of population flow a turn can declare (v0.42.0, #64). */
 export const MIGRATION_KINDS: readonly MigrationKind[] = [
  'migration',
  'refugees',
  'diaspora',
  'exodus',
 ];
 /** The three flow sizes a migration op can carry (v0.42.0, #64). */
 export const MIGRATION_SCALES: readonly MigrationScale[] = ['small', 'moderate', 'large'];
 const VALID_KINDS = new Set<string>(MIGRATION_KINDS);
 const VALID_SCALES = new Set<string>(MIGRATION_SCALES);
 /** True when `k` is one of the four known migration kinds (v0.42.0, #64). */
 export function isMigrationKind(k: unknown): k is MigrationKind {
  return typeof k === 'string' && VALID_KINDS.has(k);
 }
 /** True when `s` is one of the three known migration scales (v0.42.0, #64). */
 export function isMigrationScale(s: unknown): s is MigrationScale {
  return typeof s === 'string' && VALID_SCALES.has(s);
 }
 /**
 * (v0.42.0, #64) The DETERMINISTIC per-`scale` stat dip applied to the SOURCE
 * nation of a migration flow (the nation people leave). Each scale maps to a
 * small set of signed (negative) stat deltas: the source loses population and
 * economy. No hidden randomness — the LLM picks the scale, the table decides
 * the magnitude. Military and stability are untouched by the source dip.
 */
 export const MIGRATION_SOURCE_EFFECTS: Record<MigrationScale, Partial<Record<StatKey, number>>> = {
  small: { population: -1, economy: -1 },
  moderate: { population: -2, economy: -2 },
  large: { population: -4, economy: -3 },
 };
 /**
 * (v0.42.0, #64) The DETERMINISTIC per-`scale` stat gain applied to the
 * DESTINATION nation of a migration flow (the nation people arrive in). Each
 * scale maps to a small set of signed (positive) stat deltas: the destination
 * gains population and economy. No hidden randomness. Military and stability
 * are untouched by the base gain (the `large`-scale stability strain is applied
 * separately, see {@link LARGE_INFLUX_STABILITY_DIP}).
 */
 export const MIGRATION_DESTINATION_EFFECTS: Record<MigrationScale, Partial<Record<StatKey, number>>> =
  {
    small: { population: 1, economy: 1 },
    moderate: { population: 2, economy: 2 },
    large: { population: 3, economy: 3 },
  };
 /**
 * (v0.42.0, #64) The extra STABILITY dip applied to the destination of a
 * `large`-scale influx only — a big population surge strains a society even as
 * it grows. Added on top of the base destination gain.
 */
 export const LARGE_INFLUX_STABILITY_DIP = -2;
 /**
 * The positive-relations ladder, strongest (most positive) to weakest
 * (least positive) — the same four non-war statuses, in the order a relation
 * moves when it is nudged TOWARD the positive end. A missing relation is
 * treated as `neutral`; `war` is never touched (a war is its own entity — a
 * population flow neither fabricates nor escalates one). The `cap` in
 * {@link shiftRelationTowardPositive} is a member of this array.
 */
 const POSITIVE_ORDER: RelationStatus[] = ['ally', 'neutral', 'rival', 'hostile'];
 /**
 * (v0.42.0, #64) Nudge the bilateral relation between nations `a` and `b`
 * ONE step toward the POSITIVE end (toward `ally`) of the
 * {@link POSITIVE_ORDER} ladder, applied symmetrically to both directions, but
 * never past the given `cap`. A missing relation starts at `neutral`; a `war`
 * relation is never touched (a population flow neither fabricates nor
 * escalates a war — a warring pair is left exactly as it is). Mutates `state`
 * in place (the caller passes a clone — applyTurnResult does). Never throws.
 *
 * `cap` is the most-positive status the nudge may reach:
 *   - `refugees`   → `ally`     (hosting refugees builds the strongest goodwill)
 *   - `migration` / `diaspora` → `neutral`  (milder ties)
 *   - `exodus`     → no nudge at all
 */
 export function shiftRelationTowardPositive(
  state: GameState,
  a: string,
  b: string,
  cap: RelationStatus,
 ): void {
  const na = state.nations[a];
  const nb = state.nations[b];
  if (!na || !nb) return;
  const capIdx = POSITIVE_ORDER.indexOf(cap);
  if (capIdx === -1) return; // unknown cap: no-op (defensive)
  const step = (cur: RelationStatus | undefined): RelationStatus | null => {
    if (cur === 'war') return null; // never touch a war relation
    const s = cur ?? 'neutral'; // a missing relation is neutral
    const i = POSITIVE_ORDER.indexOf(s);
    if (i === -1) return 'neutral'; // defensive: unknown status
    if (i <= capIdx) return s; // already at or more positive than the cap: no change
    return POSITIVE_ORDER[i - 1]; // one step toward the positive end
  };
  const stepA = step(na.relations[b]);
  if (stepA !== null) na.relations[b] = stepA;
  const stepB = step(nb.relations[a]);
  if (stepB !== null) nb.relations[a] = stepB;
 }
 /**
 * (v0.42.0, #64) Validate the raw `migration` field of a turn into a safe
 * list of {@link MigrationOp}s. Defensive like the rest of the parser — never
 * throws. The raw value may be the object `{ ops: [...] }` (the TurnResult
 * shape) or a bare array (be lenient about either). Each op needs a known
 * `kind` (one of {@link MIGRATION_KINDS}), a known `scale` (one of
 * {@link MIGRATION_SCALES}), a non-empty `from` (the source nation, capped at
 * 200 chars), and — for every kind except `exodus` — a non-empty `to`
 * (the destination nation, capped at 200 chars); a non-empty `detail` is capped
 * at 300 chars. An op with an unknown / missing `kind`, an unknown / missing
 * `scale`, an empty `from`, or (for a non-`exodus` kind) an empty `to` is
 * dropped. Resolution of `from` / `to` to concrete nation ids happens at apply
 * time (`applyMigrationOp`), not here. A missing / malformed top-level value
 * yields `{ ops: [] }`.
 */
 export function validateMigrationOps(raw: unknown): MigrationOp[] {
  let list: unknown[] | null = null;
  if (Array.isArray(raw)) {
    list = raw;
  } else if (raw && typeof raw === 'object') {
    const inner = (raw as Record<string, unknown>).ops;
    if (Array.isArray(inner)) list = inner;
  }
  if (!list) return [];
  const out: MigrationOp[] = [];
  for (const e of list) {
    if (!e || typeof e !== 'object') continue;
    const o = e as Record<string, unknown>;
    if (!isMigrationKind(o.kind)) continue; // unknown / missing kind: drop
    if (!isMigrationScale(o.scale)) continue; // unknown / missing scale: drop
    const from = str(o.from, 200);
    if (!from) continue; // empty / missing source: drop
    const detail = str(o.detail, 300);
    if (o.kind === 'exodus') {
      // an exodus has no destination — `to` is optional (and ignored)
      out.push({
        kind: o.kind,
        from,
        scale: o.scale,
        ...(detail ? { detail } : {}),
      });
    } else {
      const to = str(o.to, 200);
      if (!to) continue; // non-exodus kind needs a destination: drop
      out.push({
        kind: o.kind,
        from,
        to,
        scale: o.scale,
        ...(detail ? { detail } : {}),
      });
    }
  }
  return out;
 }
 /**
 * Apply a set of signed stat `dips` to a nation's `stats` AND to every region
 * it owns that has a `regionStats` entry (clamped to 0–100), then re-derive
 * the nation's aggregate `stats` as the area×population-weighted median of its
 * regions — the same 0-region / no-entry guards as the hybrid / economy /
 * disasters layers, so a 0-region nation keeps its directly-mutated value and
 * the effect persists to the next turn. Mutates in place; never throws.
 */
 function applyNationDips(
  nation: Nation,
  dips: Partial<Record<StatKey, number>>,
  regionStats: GameState['regionStats'],
  geoOf?: (key: string) => { area: number; population: number } | undefined,
 ): void {
  (Object.keys(dips) as StatKey[]).forEach((k) => {
    const d = dips[k];
    if (typeof d === 'number') nation.stats[k] = clampStat(nation.stats[k] + d);
  });
  for (const key of nation.territory) {
    const rs = regionStats[key];
    if (!rs) continue; // a key with no entry is skipped
    (Object.keys(dips) as StatKey[]).forEach((k) => {
      const d = dips[k];
      if (typeof d === 'number') rs[k] = clampStat(rs[k] + d);
    });
  }
  // Re-derive the nation's aggregate stats so the effect persists (the main
  // recompute ran earlier this turn; without this the change would be washed
  // out next turn). A nation with no regionStats entry keeps its
  // directly-mutated `stats`.
  if (nation.territory.length > 0 && nation.territory.some((k) => regionStats[k])) {
    nation.stats = deriveNationStats(nation.territory, regionStats, geoOf);
  }
 }
 /**
 * (v0.42.0, #64) Apply ONE migration / refugee op to the (cloned) `next` state,
 * mutating it in place and never throwing. Resolution order:
 *   1. `from` must resolve to a nation (id first, then a unique name); an
 *      unknown / ambiguous source drops the op.
 *   2. For every kind except `exodus`, `to` must resolve to a nation distinct
 *      from `from` (a missing / unknown / ambiguous destination, or a
 *      self-flow, drops the op); `exodus` has no destination and skips this.
 * Then the deterministic per-`scale` effects from
 * {@link MIGRATION_SOURCE_EFFECTS} / {@link MIGRATION_DESTINATION_EFFECTS}
 * are applied:
 *   - the SOURCE nation loses population and economy (all four kinds,
 *     including `exodus`) — for a non-`exodus` op this is applied only AFTER
 *     the destination is validated, so a self-flow or a bad destination drops
 *     the op entirely and never touches the source;
 *   - for a non-`exodus` kind the DESTINATION gains population and economy,
 *     and a `large` influx additionally strains its stability by
 *     {@link LARGE_INFLUX_STABILITY_DIP};
 *   - each affected nation's derived `stats` are re-derived afterwards (the
 *     same 0-region / no-entry guards, so the effect persists);
 *   - for a non-`exodus` kind the from↔to relation moves one step toward the
 *     positive end of the ladder (cap `ally` for `refugees`, `neutral` for
 *     `migration` / `diaspora`; a `war` relation is left untouched).
 * The op never moves territory (sole ownership is untouched) and never creates
 * or escalates a war.
 */
 export function applyMigrationOp(
  next: GameState,
  op: MigrationOp,
  geoOf?: (key: string) => { area: number; population: number } | undefined,
 ): void {
  const from = resolveNationRef(next, op.from);
  if (from === null) return; // unknown / ambiguous source: drop
  const source = next.nations[from];
  if (!source) return; // defensive: resolved id has no nation record
  if (op.kind === 'exodus') {
    // An exodus has no destination: the source loses population and economy
    // and that is all (no gain, no relation nudge).
    applyNationDips(source, MIGRATION_SOURCE_EFFECTS[op.scale], next.regionStats, geoOf);
    return;
  }
  // Non-exodus: resolve the destination FIRST and drop the WHOLE op (including
  // the source dip) when it is missing / unknown / ambiguous or a self-flow —
  // so a self-flow or a bad destination never touches the source.
  const to = op.to;
  if (!to) return; // defensive: a non-exodus op should always have a `to`
  const destId = resolveNationRef(next, to);
  if (destId === null || destId === from) return; // unknown / self destination: drop
  const dest = next.nations[destId];
  if (!dest) return; // defensive
  // The source loses population and economy (every non-exodus kind reaches
  // here; the exodus path already applied its source dip and returned).
  applyNationDips(source, MIGRATION_SOURCE_EFFECTS[op.scale], next.regionStats, geoOf);
  // The destination gains population and economy; a large influx also strains
  // its stability.
  const destDips: Partial<Record<StatKey, number>> = { ...MIGRATION_DESTINATION_EFFECTS[op.scale] };
  if (op.scale === 'large') {
    destDips.stability = (destDips.stability ?? 0) + LARGE_INFLUX_STABILITY_DIP;
  }
  applyNationDips(dest, destDips, next.regionStats, geoOf);
  // The from↔to relation moves one step toward the positive end, capped by
  // kind (a `war` relation is left untouched by shiftRelationTowardPositive).
  const cap: RelationStatus = op.kind === 'refugees' ? 'ally' : 'neutral';
  shiftRelationTowardPositive(next, from, destId, cap);
 }
 export const migration: Ability<'migration'> = {
  field: 'migration',
  default: () => ({ ops: [] }),
  // The low-level validator returns a bare list; the field's shape is the
  // `{ ops }` object (mirrors the historical TurnResult shape).
  validate: (raw) => ({ ops: validateMigrationOps(raw) }),
  apply: (state, data, ctx) => {
    for (const op of data.ops) {
      applyMigrationOp(state, op, ctx.geoOf);
    }
  },
  schemaLine: () =>
    '  "migration": {"ops":[{"kind":"<migration|refugees|diaspora|exodus>","from":"<nation id or name>","to":"<nation id or name>","scale":"<small|moderate|large>","detail":"<short detail>"}]},',
  constraint: () =>
    '- Migration & refugees ("migration.ops") are people moving between nations this turn: a "kind" ("migration", "refugees", "diaspora", or "exodus"), a "from" (the source nation — id or name), a "to" (the destination nation — required for every kind except "exodus", which has no destination), and a "scale" (small / moderate / large). The engine applies a DETERMINISTIC effect (no hidden randomness): the source LOSES a small amount of population and economy, the destination GAINS a small amount of population and economy (a "large" influx additionally strains the destination\'s stability by 2), and the from↔to relation moves one step toward the positive end of the ally/neutral/rival/hostile ladder — capped at "ally" for "refugees" (hosting refugees builds the strongest goodwill), capped at "neutral" for "migration"/"diaspora" (milder ties), and not at all for "exodus"; the nudge never creates or escalates a "war" (a warring pair is left untouched). The layer is turn-transient (no memory): a continuing flow is simply RE-DECLARED each turn it persists. It never moves borders — sole ownership is untouched. Propose at most 1-2 per turn and narrate each one in "events" (a "social" or "diplomatic" event).',
  isMeaningful: (data) => data.ops.length > 0,
  stub: () => ({ ops: [] }),
  // The layer is turn-transient — it contributes nothing to the user payload
  // (no durable state to show the model), so the payload is always empty.
  payload: () => ({}),
 };
@@ -12,7 +12,7 @@
 //      by the disasters feature (its payload is always empty).
 //
 //   2. REGISTRY CONTRACT — the ABILITIES registry is the canonical ordered
-//      list of the 9 abilities; each ability's default() equals the canonical
+//      list of the 11 abilities; each ability's default() equals the canonical
 //      TurnResult default for its field, is a FRESH value (never a shared
 //      reference), its default is not "meaningful" while a populated value is,
 //      and the registry composes (a hypothetical extra ability can be appended
@@ -31,6 +31,7 @@ import {
  activeWarPairs,
  applyDisasterEvent,
  applyIndustryEffects,
  applyMigrationOp,
  atWar,
  buildSystemPrompt,
  buildUserPrompt,
@@ -44,10 +45,18 @@ import {
  isDisasterType,
  isHybridOpType,
  isIndustryType,
  isMigrationKind,
  isMigrationScale,
  LARGE_INFLUX_STABILITY_DIP,
  MIGRATION_DESTINATION_EFFECTS,
  MIGRATION_KINDS,
  MIGRATION_SCALES,
  MIGRATION_SOURCE_EFFECTS,
  NEW_NATION_STATS,
  resolveNationRef,
  resolveRegionKey,
  shiftRelationTowardHostile,
  shiftRelationTowardPositive,
  syncWarRelations,
  validateDisasterEvents,
  validateEconomyOps,
@@ -55,9 +64,18 @@ import {
  validateIdeologyOps,
  validateIndustryOps,
  validateLeaderOps,
  validateMigrationOps,
  validateNuclearOps,
  validateTakeovers,
  validateWarOps,
  validateSeaOps,
  applySeaControl,
  applySeaZoneBonuses,
  SEA_ZONE_BONUS,
  SEA_ZONES,
  SEA_ZONE_IDS,
  isSeaZoneId,
  seaZoneName,
 } from '../engine';
 import { createPresetStore } from '../presets';
 import { ABILITIES } from './index';
@@ -71,6 +89,7 @@ import type {
  RegionResources,
  RelationStatus,
  RoundItem,
  SeaZoneClaim,
  TradeAgreement,
 } from '../../shared/types';
 import type { MarkerInfo, TurnResult, WarInfo } from '../../shared/protocol';
@@ -144,6 +163,8 @@ const state: GameState = {
  trades: [],
  embargoes: [],
  industry: [],
  // (v0.43.0, #65) no sea-zone control on a fresh state.
  seaZones: [],
 };
 // --- buildUserPrompt arguments: every optional branch exercised. ---
@@ -180,6 +201,7 @@ const nationResources: Record<string, RegionResources> = {
 };
 const industryProjects: IndustryProject[] = [{ regionKey: 'a-r1', type: 'industry' }];
 const nuclear: Record<string, boolean> = { a1: true, b2: false, c3: false };
 const seaZones: SeaZoneClaim[] = [];
 /**
 * Assert the current prompt output is byte-identical to the committed golden —
@@ -217,6 +239,8 @@ function fullDefaultTurn(): TurnResult {
    leaders: { changes: [] },
    ideology: { changes: [] },
    disasters: { events: [] },
    migration: { ops: [] },
    sea: { control: [] },
    markers: { add: [], remove: [] },
  };
 }
@@ -242,11 +266,15 @@ function meaningfulFor(field: AbilityField): TurnResult[AbilityField] {
      return { changes: [{ target: 'a1', to: 'democracy' }] };
    case 'disasters':
      return { events: [{ type: 'earthquake', target: 'a1', severity: 'minor' }] };
    case 'migration':
      return { ops: [{ kind: 'migration', from: 'a1', to: 'b2', scale: 'small' }] };
    case 'sea':
      return { control: [{ zone: 'pacific', by: 'a1' }] };
  }
 }
 describe('ABILITIES registry (v0.40.0, #67)', () => {
-  it('is the canonical 9-ability order (takeovers → disasters)', () => {
+  it('is the canonical 11-ability order (takeovers → sea)', () => {
    expect(ABILITIES.map((a) => a.field)).toEqual([
      'takeovers',
      'wars',
@@ -257,13 +285,15 @@ describe('ABILITIES registry (v0.40.0, #67)', () => {
      'leaders',
      'ideology',
      'disasters',
      'migration',
      'sea',
    ]);
  });
-  it('lists 9 distinct fields, each a key of TurnResult', () => {
+  it('lists 11 distinct fields, each a key of TurnResult', () => {
    const fields = ABILITIES.map((a) => a.field);
-    expect(fields).toHaveLength(9);
+    expect(fields).toHaveLength(11);
-    expect(new Set(fields).size).toBe(9);
+    expect(new Set(fields).size).toBe(11);
    const all = fullDefaultTurn();
    for (const f of fields) expect(f in all).toBe(true);
  });
@@ -293,6 +323,7 @@ describe('ABILITIES registry (v0.40.0, #67)', () => {
        nationResources,
        industryProjects,
        nuclear,
        seaZones,
      ),
    );
  });
@@ -322,13 +353,13 @@ describe('ABILITIES registry (v0.40.0, #67)', () => {
  it('declares exactly the durable GameState fields the db migration must default', () => {
    const owned: string[] = [];
    for (const a of ABILITIES) if (a.stateFields) owned.push(...a.stateFields);
-    expect([...owned].sort()).toEqual(['embargoes', 'industry', 'trades', 'wars']);
+    expect([...owned].sort()).toEqual(['embargoes', 'industry', 'seaZones', 'trades', 'wars']);
  });
  it('composes: a hypothetical extra ability can be appended and every uniform loop still runs', () => {
    // The registry is a plain ordered array the engine iterates uniformly. A
    // structural (field-name-agnostic) loop over the abilities — schema line,
-    // constraint bullet — must keep working when a 10th ability is appended.
+    // constraint bullet — must keep working when an 11th ability is appended.
    // This documents the extension point without widening the closed
    // AbilityField union.
    interface Loopable {
@@ -347,9 +378,9 @@ describe('ABILITIES registry (v0.40.0, #67)', () => {
      'custom',
    ]);
    // every uniform loop runs over all N abilities, the appended one included:
-    expect(extended.map((a) => a.schemaLine())).toHaveLength(10);
+    expect(extended.map((a) => a.schemaLine())).toHaveLength(12);
-    expect(extended.map((a) => a.constraint())).toHaveLength(10);
+    expect(extended.map((a) => a.constraint())).toHaveLength(12);
-    expect(extended[9].schemaLine()).toBe('  "custom": [],');
+    expect(extended[11].schemaLine()).toBe('  "custom": [],');
  });
  it('the engine still re-exports every name its callers import from it', () => {
@@ -388,6 +419,26 @@ describe('ABILITIES registry (v0.40.0, #67)', () => {
      DISASTER_TYPES,
      DISASTER_SEVERITIES,
      DISASTER_EFFECTS,
      // migration (v0.42.0, #64)
      validateMigrationOps,
      applyMigrationOp,
      shiftRelationTowardPositive,
      isMigrationKind,
      isMigrationScale,
      MIGRATION_KINDS,
      MIGRATION_SCALES,
      MIGRATION_SOURCE_EFFECTS,
      MIGRATION_DESTINATION_EFFECTS,
      LARGE_INFLUX_STABILITY_DIP,
      // sea (v0.43.0, #65)
      validateSeaOps,
      applySeaControl,
      applySeaZoneBonuses,
      SEA_ZONE_BONUS,
      SEA_ZONES,
      SEA_ZONE_IDS,
      isSeaZoneId,
      seaZoneName,
    };
    for (const [name, value] of Object.entries(reexported)) {
      expect(value, `engine should re-export ${name}`).toBeDefined();
@@ -0,0 +1,494 @@
 // Unit tests for the SEA (naval / sea control) ability (v0.43.0, #65) — the
 // modular, DURABLE LLM-ability that gives nations sole control over a fixed
 // set of 12 named sea zones: the zone is upserted in `GameState.seaZones`
 // (replace in place, contest by higher current military), and every committed
 // turn the controller earns a deterministic +1 military / +1 economy bonus
 // (clamped, mirrored to its regions, re-derived). The layer never touches
 // `territory` / `unowned` — it is fully parallel to but independent of land.
 // This is the ability's own test file (the registry's cross-cutting
 // guarantees — order, distinct fields, the system/user goldens — are covered
 // by ./registry.test.ts). The stub never proposes a sea op, so the apply path
 // is exercised here, not by the e2e suite.
 import { describe, expect, it } from 'vitest';
 import {
  SEA_ZONES,
  SEA_ZONE_IDS,
  applySeaControl,
  applySeaZoneBonuses,
  isSeaZoneId,
  sea,
  seaZoneName,
  validateSeaOps,
 } from './sea';
 import type {
  GameState,
  Nation,
  NationStats,
  RegionStats,
  SeaZoneClaim,
 } from '../../shared/types';
 // ---------------------------------------------------------------------------
 // Fixture helpers
 // ---------------------------------------------------------------------------
 /** Build a NationStats from the four canonical indices (military, economy, stability, population). */
 function NS(military: number, economy: number, stability: number, population: number): NationStats {
  return { military, economy, stability, population };
 }
 /** Build a RegionStats from the four canonical indices. */
 function RS(military: number, economy: number, stability: number, population: number): RegionStats {
  return { military, economy, stability, population };
 }
 /** A minimal nation: the given id/name/stats/region-key territory. */
 function mkNation(
  id: string,
  name: string,
  stats: NationStats,
  territory: string[],
 ): Nation {
  return { id, name, type: 'major', stats, territory, relations: {} };
 }
 /**
 * A minimal GameState carrying the given nations (keyed by id), per-region
 * stats, and an optional existing sea-zone list. Every other required field
 * is at its fresh-game baseline.
 */
 function mkState(
  nations: Record<string, Nation>,
  regionStats: Record<string, RegionStats>,
  seaZones: SeaZoneClaim[] = [],
 ): GameState {
  return {
    id: 'g1',
    presetId: 'test',
    presetTitle: 'Test',
    playerNationId: Object.keys(nations)[0] ?? 'a1',
    turn: 1,
    date: '1939-09-01',
    nations,
    events: [],
    pending: [],
    version: 1,
    unowned: [],
    pendingNationOps: [],
    markers: [],
    regionStats,
    wars: [],
    trades: [],
    embargoes: [],
    industry: [],
    seaZones,
  };
 }
 // ---------------------------------------------------------------------------
 // SEA_ZONES / isSeaZoneId / seaZoneName
 // ---------------------------------------------------------------------------
 describe('SEA_ZONES / SEA_ZONE_IDS / isSeaZoneId / seaZoneName', () => {
  it('exposes exactly the 12 fixed sea zones', () => {
    expect(SEA_ZONES).toHaveLength(12);
    const ids = SEA_ZONES.map((z) => z.id);
    expect(ids).toEqual([
      'north-atlantic',
      'south-atlantic',
      'pacific',
      'indian',
      'mediterranean',
      'north-sea',
      'baltic',
      'arctic',
      'black-sea',
      'gulf-mexico',
      'red-sea',
      'sargasso',
    ]);
  });
  it('SEA_ZONE_IDS is a ReadonlySet of all 12 ids', () => {
    expect(SEA_ZONE_IDS).toBeInstanceOf(Set);
    expect(SEA_ZONE_IDS.size).toBe(12);
    for (const z of SEA_ZONES) expect(SEA_ZONE_IDS.has(z.id)).toBe(true);
  });
  it('isSeaZoneId accepts each known id and rejects unknown / non-strings', () => {
    for (const z of SEA_ZONES) expect(isSeaZoneId(z.id)).toBe(true);
    expect(isSeaZoneId('atlantic-ocean')).toBe(false);
    expect(isSeaZoneId('')).toBe(false);
  });
  it('seaZoneName returns the human-readable name; an unknown id is returned raw', () => {
    expect(seaZoneName('pacific')).toBe('Pacific Ocean');
    expect(seaZoneName('mediterranean')).toBe('Mediterranean Sea');
    expect(seaZoneName('nope')).toBe('nope');
  });
 });
 // ---------------------------------------------------------------------------
 // validateSeaOps
 // ---------------------------------------------------------------------------
 describe('validateSeaOps', () => {
  it('accepts the { control: [...] } object shape and a bare array', () => {
    const op = { zone: 'pacific', by: 'a1' };
    expect(validateSeaOps({ control: [op] })).toEqual({ control: [op] });
    expect(validateSeaOps([op])).toEqual({ control: [op] });
  });
  it('drops an op with an unknown / missing zone', () => {
    expect(validateSeaOps([{ zone: 'nope', by: 'a1' }])).toEqual({ control: [] });
    expect(validateSeaOps([{ by: 'a1' }])).toEqual({ control: [] });
    expect(validateSeaOps([{ zone: '', by: 'a1' }])).toEqual({ control: [] });
  });
  it('drops an op with an empty / missing `by` (the controller)', () => {
    expect(validateSeaOps([{ zone: 'pacific', by: '' }])).toEqual({ control: [] });
    expect(validateSeaOps([{ zone: 'pacific' }])).toEqual({ control: [] });
  });
  it('drops a non-object entry', () => {
    expect(validateSeaOps([42, 'nope', null, { zone: 'pacific', by: 'a1' }])).toEqual({
      control: [{ zone: 'pacific', by: 'a1' }],
    });
  });
  it('a missing / malformed top-level value yields { control: [] }', () => {
    expect(validateSeaOps(undefined)).toEqual({ control: [] });
    expect(validateSeaOps(null)).toEqual({ control: [] });
    expect(validateSeaOps('nope')).toEqual({ control: [] });
    expect(validateSeaOps({ control: 'nope' })).toEqual({ control: [] });
  });
  it('caps `zone` at 100 and `by` at 200 chars', () => {
    const longBy = 'f'.repeat(500);
    const out = validateSeaOps([{ zone: 'pacific', by: longBy }]);
    expect(out.control).toHaveLength(1);
    expect(out.control[0].by).toHaveLength(200);
  });
 });
 // ---------------------------------------------------------------------------
 // applySeaControl
 // ---------------------------------------------------------------------------
 describe('applySeaControl', () => {
  it('a single op sets a new zone claim', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
    );
    applySeaControl(state, [{ zone: 'pacific', by: 'a1' }]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
  });
  it('replaces an existing claim in place (position preserved)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(90, 40, 20, 30), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(90, 40, 20, 30) },
      [
        { zone: 'pacific', by: 'a1' },
        { zone: 'indian', by: 'b2' },
      ],
    );
    // b2 now claims pacific — the pacific claim moves to b2 but stays at index 0
    applySeaControl(state, [{ zone: 'pacific', by: 'b2' }]);
    expect(state.seaZones).toEqual([
      { zone: 'pacific', by: 'b2' },
      { zone: 'indian', by: 'b2' },
    ]);
  });
  it('appends a new zone after existing claims', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    applySeaControl(state, [{ zone: 'arctic', by: 'a1' }]);
    expect(state.seaZones).toEqual([
      { zone: 'pacific', by: 'a1' },
      { zone: 'arctic', by: 'a1' },
    ]);
  });
  it('a contest: the higher current military wins', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(90, 40, 20, 30), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(90, 40, 20, 30) },
    );
    // b2 has higher military (90 > 80) → b2 wins
    applySeaControl(state, [
      { zone: 'pacific', by: 'a1' },
      { zone: 'pacific', by: 'b2' },
    ]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'b2' }]);
  });
  it('a contest tie: the earlier-listed op wins', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(50, 50, 50, 50), ['b-r1']),
      },
      { 'a-r1': RS(50, 50, 50, 50), 'b-r1': RS(50, 50, 50, 50) },
    );
    // equal military (50 == 50) → a1 wins (listed first)
    applySeaControl(state, [
      { zone: 'pacific', by: 'a1' },
      { zone: 'pacific', by: 'b2' },
    ]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
  });
  it('two ops for the same nation on the same zone: a single claim (no contest)', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
    );
    applySeaControl(state, [
      { zone: 'pacific', by: 'a1' },
      { zone: 'pacific', by: 'a1' },
    ]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
  });
  it('resolves `by` by unique name (not just id)', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
    );
    applySeaControl(state, [{ zone: 'pacific', by: 'Alpha' }]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
  });
  it('an unresolvable `by` is dropped; if all ops on a zone drop, the zone is untouched', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']) },
      { 'a-r1': RS(80, 70, 60, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    // ghost does not exist → dropped; pacific stays as a1
    applySeaControl(state, [{ zone: 'pacific', by: 'ghost' }]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
    // a NEW zone with only an unresolvable op → zone not added
    applySeaControl(state, [{ zone: 'arctic', by: 'ghost' }]);
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
  });
  it('an ambiguous name (two nations share it) drops the op', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Twin', NS(80, 70, 60, 50), ['a-r1']),
        a2: mkNation('a2', 'Twin', NS(20, 20, 20, 20), ['a-r2']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'a-r2': RS(20, 20, 20, 20) },
    );
    applySeaControl(state, [{ zone: 'pacific', by: 'Twin' }]);
    // ambiguous → dropped
    expect(state.seaZones).toEqual([]);
  });
  it('never touches `territory` or `unowned`', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(80, 70, 60, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(90, 40, 20, 30), ['b-r1']),
      },
      { 'a-r1': RS(80, 70, 60, 50), 'b-r1': RS(90, 40, 20, 30) },
    );
    applySeaControl(state, [
      { zone: 'pacific', by: 'a1' },
      { zone: 'pacific', by: 'b2' },
    ]);
    expect(state.nations.a1.territory).toEqual(['a-r1']);
    expect(state.nations.b2.territory).toEqual(['b-r1']);
    expect(state.unowned).toEqual([]);
  });
 });
 // ---------------------------------------------------------------------------
 // applySeaZoneBonuses
 // ---------------------------------------------------------------------------
 describe('applySeaZoneBonuses', () => {
  it('a controller earns +1 military and +1 economy (clamped, mirrored, re-derived)', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    applySeaZoneBonuses(state);
    // +1 to both military and economy, mirrored to the region, re-derived
    // (single region → re-derive gives back the region's value)
    expect(state.nations.a1.stats).toEqual(NS(51, 51, 50, 50));
    expect(state.regionStats['a-r1']).toEqual(RS(51, 51, 50, 50));
  });
  it('clamps to 0 and 100', () => {
    // military at 99 → 100; economy at 1 → 2
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(99, 1, 50, 50), ['a-r1']) },
      { 'a-r1': RS(99, 1, 50, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    applySeaZoneBonuses(state);
    expect(state.nations.a1.stats.military).toBe(100);
    expect(state.nations.a1.stats.economy).toBe(2);
  });
  it('a nation controlling several zones stacks the bonus', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [
        { zone: 'pacific', by: 'a1' },
        { zone: 'indian', by: 'a1' },
      ],
    );
    applySeaZoneBonuses(state);
    // +2 to both (one per zone)
    expect(state.nations.a1.stats).toEqual(NS(52, 52, 50, 50));
  });
  it('a 0-region nation keeps its directly-mutated stats (no re-derive)', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), []) },
      {},
      [{ zone: 'pacific', by: 'a1' }],
    );
    applySeaZoneBonuses(state);
    // direct mutation, no re-derive (no regions)
    expect(state.nations.a1.stats).toEqual(NS(51, 51, 50, 50));
  });
  it('a stale controller (nation no longer in `nations`) is skipped; the claim is kept', () => {
    // Build a state where the claim references a nation id that is not in `nations`
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [{ zone: 'pacific', by: 'ghost' }],
    );
    applySeaZoneBonuses(state);
    // ghost is not in nations → skipped; a1 is unaffected
    expect(state.nations.a1.stats).toEqual(NS(50, 50, 50, 50));
    // the claim is kept (not removed)
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'ghost' }]);
  });
  it('an empty seaZones list is a no-op', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [],
    );
    applySeaZoneBonuses(state);
    expect(state.nations.a1.stats).toEqual(NS(50, 50, 50, 50));
  });
  it('never touches `territory` or `unowned`', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    applySeaZoneBonuses(state);
    expect(state.nations.a1.territory).toEqual(['a-r1']);
    expect(state.unowned).toEqual([]);
  });
 });
 // ---------------------------------------------------------------------------
 // The Ability object contract
 // ---------------------------------------------------------------------------
 describe('sea ability', () => {
  it('owns the "sea" field; default() is a fresh empty { control: [] }', () => {
    expect(sea.field).toBe('sea');
    expect(sea.default()).toEqual({ control: [] });
    expect(sea.default()).not.toBe(sea.default());
  });
  it('default() is not meaningful; a populated value is', () => {
    expect(sea.isMeaningful(sea.default())).toBe(false);
    expect(sea.isMeaningful({ control: [{ zone: 'pacific', by: 'a1' }] })).toBe(true);
  });
  it('validate() wraps the validator into the SeaOps shape', () => {
    expect(sea.validate([{ zone: 'pacific', by: 'a1' }])).toEqual({
      control: [{ zone: 'pacific', by: 'a1' }],
    });
    expect(sea.validate(undefined)).toEqual({ control: [] });
  });
  it('the stub value equals default() (the stub never proposes a sea op)', () => {
    expect(sea.stub()).toEqual({ control: [] });
  });
  it('stateFields is [seaZones] (the durable GameState field)', () => {
    expect(sea.stateFields).toEqual(['seaZones']);
  });
  it('payload() emits seaZones (even when empty / undefined)', () => {
    expect(sea.payload({ seaZones: [] } as never)).toEqual({ seaZones: [] });
    expect(sea.payload({} as never)).toEqual({ seaZones: [] });
    expect(sea.payload({ seaZones: [{ zone: 'pacific', by: 'a1' }] } as never)).toEqual({
      seaZones: [{ zone: 'pacific', by: 'a1' }],
    });
  });
  it('apply() runs the ops then the per-turn bonus (no throw on a bad ref)', () => {
    const state = mkState(
      {
        a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']),
        b2: mkNation('b2', 'Bravo', NS(80, 40, 20, 30), ['b-r1']),
      },
      { 'a-r1': RS(50, 50, 50, 50), 'b-r1': RS(80, 40, 20, 30) },
    );
    const ctx = { previous: state, actingTurn: state.turn };
    sea.apply(
      state,
      {
        control: [
          { zone: 'pacific', by: 'a1' },
          { zone: 'pacific', by: 'b2' },
          // an unresolvable ref — must be dropped, not throw
          { zone: 'arctic', by: 'ghost' },
        ],
      },
      ctx,
    );
    // contest: b2 (military 80) beats a1 (military 50) → b2 controls pacific
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'b2' }]);
    // b2 gets the +1/+1 bonus (it controls pacific)
    expect(state.nations.b2.stats).toEqual(NS(81, 41, 20, 30));
    // a1 is unaffected
    expect(state.nations.a1.stats).toEqual(NS(50, 50, 50, 50));
  });
  it('apply() with an empty control still applies the per-turn bonus to existing claims', () => {
    const state = mkState(
      { a1: mkNation('a1', 'Alpha', NS(50, 50, 50, 50), ['a-r1']) },
      { 'a-r1': RS(50, 50, 50, 50) },
      [{ zone: 'pacific', by: 'a1' }],
    );
    const ctx = { previous: state, actingTurn: state.turn };
    sea.apply(state, { control: [] }, ctx);
    // no new claims, but the existing claim's controller earns the bonus
    expect(state.seaZones).toEqual([{ zone: 'pacific', by: 'a1' }]);
    expect(state.nations.a1.stats).toEqual(NS(51, 51, 50, 50));
  });
 });
@@ -0,0 +1,210 @@
 // The SEA (naval / sea control) ability (v0.43.0, #65) as a modular
 // LLM-ability (v0.40.0, #67) — the naval layer, fully parallel to but
 // INDEPENDENT of land. The world has a fixed set of 12 named SEA ZONES
 // (`SEA_ZONES` in shared/protocol.ts); each is under the SOLE CONTROL of at
 // most one nation. Controlling a sea zone never moves land (`territory` /
 // `unowned` are untouched) and moving land never touches a sea zone.
 //
 // Each turn the LLM declares `sea.control` ops — one op names the zone and
 // the nation that (now) controls it. The engine resolves `by` (id first, then
 // a case-insensitive unique name, via the shared `resolveNationRef`) and
 // UPSERTS the zone's claim in `GameState.seaZones` (replace in place if the
 // zone is already claimed, append if new). If two or more ops this turn claim
 // the SAME zone for DIFFERENT resolved nations, the zone is CONTESTED: the
 // higher current `stats.military` wins (a tie goes to the op listed earlier in
 // the `control` array) — deterministic, no hidden randomness. An unresolvable
 // `by` is dropped (never thrown).
 //
 // Every committed turn — INCLUDING a turn with an empty `control` — each
 // existing claim's controller earns a small DETERMINISTIC bonus
 // (`SEA_ZONE_BONUS = 1` military + 1 economy, clamped to 0–100, mirrored to
 // the controller's regions and re-derived with the same 0-region / no-entry
 // guards as the economy / migration layers); a claim whose nation no longer
 // exists is skipped (the claim is kept, never thrown). The layer is DURABLE
 // (unlike the turn-transient hybrid / disasters / migration layers):
 // `GameState.seaZones` persists across turns and in SQLite, and the user
 // payload always carries the current `seaZones` list (even when empty).
 import {
  clampStat,
  deriveNationStats,
  isSeaZoneId,
 } from '../../shared/protocol';
 export { SEA_ZONES, SEA_ZONE_IDS, isSeaZoneId, seaZoneName } from '../../shared/protocol';
 import type { SeaControlOp, SeaOps } from '../../shared/protocol';
 import type { GameState, Nation } from '../../shared/types';
 import { resolveNationRef, str } from './shared';
 import type { Ability } from './types';
 /**
 * (v0.43.0, #65) The DETERMINISTIC per-turn bonus each sea-zone controller
 * earns (applied to BOTH `military` and `economy`, clamped to 0–100, mirrored
 * to the controller's regions, and re-derived with the same 0-region /
 * no-entry guards as the economy / migration layers). No hidden randomness.
 */
 export const SEA_ZONE_BONUS = 1;
 /**
 * (v0.43.0, #65) Validate the raw `sea` field of a turn into a safe
 * {@link SeaOps}. Defensive like the rest of the parser — never throws. The
 * raw value may be the object `{ control: [...] }` (the TurnResult shape) or
 * a bare array (be lenient about either). Each op needs a valid `zone` (one of
 * {@link SEA_ZONES}) and a non-empty `by` (the controlling nation's id or
 * unique name, capped at 200 chars). An op with an unknown / missing `zone` or
 * an empty / missing `by` is dropped. Resolution of `by` to a concrete nation
 * id happens at apply time (`applySeaControl`), not here. A missing /
 * malformed top-level value yields `{ control: [] }`.
 */
 export function validateSeaOps(raw: unknown): SeaOps {
  const out: SeaOps = { control: [] };
  let list: unknown[] | null = null;
  if (Array.isArray(raw)) {
    list = raw;
  } else if (raw && typeof raw === 'object') {
    const inner = (raw as Record<string, unknown>).control;
    if (Array.isArray(inner)) list = inner;
  }
  if (!list) return out;
  for (const e of list) {
    if (!e || typeof e !== 'object') continue;
    const o = e as Record<string, unknown>;
    const zone = str(o.zone, 100);
    if (!zone || !isSeaZoneId(zone)) continue; // unknown / missing zone: drop
    const by = str(o.by, 200);
    if (!by) continue; // empty / missing controller: drop
    out.control.push({ zone, by });
  }
  return out;
 }
 /**
 * (v0.43.0, #65) Upsert the turn's sea-control ops into `next.seaZones`,
 * mutating in place and never throwing. Each op's `by` is resolved against the
 * CURRENT state (id first, then a case-insensitive unique name) — an
 * unresolvable ref is dropped. Per zone (in first-appearance order): a single
 * surviving op SETS or REPLACES the zone's controller (replace the existing
 * entry in place — preserving its position — or append a new one); two or
 * more surviving ops on the same zone for DIFFERENT resolved nations make the
 * zone CONTESTED — the higher current `stats.military` wins (a tie goes to the
 * op listed earlier in the `control` array), and the winner becomes the
 * controller. A zone whose ops all resolve to the same nation is simply (re-)
 * set to that nation. Sea control never touches `territory` / `unowned`.
 */
 export function applySeaControl(next: GameState, ops: SeaControlOp[]): void {
  // Group the ops by zone, keeping the original (first-appearance) order of
  // zones and each zone's ops (so the contest tie-break "earlier in the
  // control array" is well-defined).
  const byZone = new Map<string, { index: number; by: string }[]>();
  ops.forEach((op, index) => {
    const list = byZone.get(op.zone) ?? [];
    list.push({ index, by: op.by });
    byZone.set(op.zone, list);
  });
  for (const [zone, list] of byZone) {
    // Resolve each op's `by`; an unresolvable ref is dropped (the zone is
    // still decided by the ops that do resolve).
    const resolved = list
      .map(({ index, by }) => ({ index, id: resolveNationRef(next, by) }))
      .filter((r): r is { index: number; id: string } => r.id !== null);
    if (resolved.length === 0) continue; // nothing resolved: zone untouched
    // Contest: the highest current `stats.military` wins; a strict `>` keeps
    // the EARLIER-listed op on a tie (the list is in control-array order).
    let winner = resolved[0];
    for (const r of resolved) {
      const mw = next.nations[winner.id]?.stats.military ?? 0;
      const mr = next.nations[r.id]?.stats.military ?? 0;
      if (mr > mw) winner = r;
    }
    const existing = next.seaZones.find((c) => c.zone === zone);
    if (existing) {
      existing.by = winner.id; // replace in place (position preserved)
    } else {
      next.seaZones.push({ zone, by: winner.id });
    }
  }
 }
 /**
 * (v0.43.0, #65) The per-turn sea bonus, applied EVERY committed turn (not
 * just to this turn's claims): each entry of `next.seaZones` grants its
 * controller `SEA_ZONE_BONUS` military + `SEA_ZONE_BONUS` economy (clamped
 * to 0–100, mirrored to every region the nation owns, then the nation's
 * derived `stats` re-derived — the same 0-region / no-entry guards as the
 * economy / migration layers, so a 0-region nation keeps its directly-mutated
 * value). A nation controlling several zones stacks the bonus; a claim whose
 * nation no longer exists (removed by a merge / split this turn) is skipped —
 * the claim is kept, never thrown. Never throws.
 */
 export function applySeaZoneBonuses(
  next: GameState,
  geoOf?: (key: string) => { area: number; population: number } | undefined,
 ): void {
  if (next.seaZones.length === 0) return;
  // nation id -> {military, economy} delta (claims for the same nation stack).
  const delta = new Map<string, { military: number; economy: number }>();
  for (const c of next.seaZones) {
    const d = delta.get(c.by) ?? { military: 0, economy: 0 };
    d.military += SEA_ZONE_BONUS;
    d.economy += SEA_ZONE_BONUS;
    delta.set(c.by, d);
  }
  const applyNation = (n: Nation, d: { military: number; economy: number }): void => {
    (['military', 'economy'] as const).forEach((k) => {
      n.stats[k] = clampStat(n.stats[k] + d[k]);
    });
    for (const key of n.territory) {
      const rs = next.regionStats[key];
      if (!rs) continue; // a key with no entry is skipped
      (['military', 'economy'] as const).forEach((k) => {
        rs[k] = clampStat(rs[k] + d[k]);
      });
    }
    // Re-derive the nation's aggregate stats so the effect persists (the main
    // recompute ran earlier this turn; without this the change would be washed
    // out next turn). A nation with no regionStats entry keeps its
    // directly-mutated `stats`.
    if (n.territory.length > 0 && n.territory.some((k) => next.regionStats[k])) {
      n.stats = deriveNationStats(n.territory, next.regionStats, geoOf);
    }
  };
  for (const [id, d] of delta) {
    const n = next.nations[id];
    if (!n) continue; // a nation removed this turn: the bonus is dropped (claim kept)
    applyNation(n, d);
  }
 }
 export const sea: Ability<'sea'> = {
  field: 'sea',
  default: () => ({ control: [] }),
  validate: (raw) => validateSeaOps(raw),
  apply: (state, data, ctx) => {
    // (1) APPLY OPS: this turn's control ops upsert `GameState.seaZones`
    //     (a single op sets/replaces the zone's controller; a same-zone
    //     contest goes to the higher current `stats.military`, a tie to the
    //     earlier-listed op).
    // (2) PER-TURN BONUS: EVERY committed turn — including this one, and
    //     including turns with an empty `control` — each existing claim's
    //     controller earns the deterministic military/economy bonus, so a
    //     zone that stays held keeps paying out.
    applySeaControl(state, data.control);
    applySeaZoneBonuses(state, ctx.geoOf);
  },
  schemaLine: () =>
    '  "sea": {"control":[{"zone":"<seaZoneId>","by":"<nation id or name>"}]},',
  constraint: () =>
    '- Sea control ("sea") is the naval layer, fully parallel to but INDEPENDENT of land: each of the 12 fixed sea zones — "north-atlantic" (North Atlantic), "south-atlantic" (South Atlantic), "pacific" (Pacific Ocean), "indian" (Indian Ocean), "mediterranean" (Mediterranean Sea), "north-sea" (North Sea), "baltic" (Baltic Sea), "arctic" (Arctic Ocean), "black-sea" (Black Sea), "gulf-mexico" (Gulf of Mexico), "red-sea" (Red Sea), "sargasso" (Sargasso Sea) — is under the SOLE control of at most one nation. A control op ({"zone":"<id>","by":"<nation>"}) sets or replaces that zone\'s controller (the user message\'s "seaZones" field lists who controls what now); if two or more ops this turn claim the SAME zone for DIFFERENT nations, the zone is CONTESTED and the higher current "military" wins (a tie goes to the earlier-listed op). Every committed turn each zone\'s controller earns a small deterministic +1 military and +1 economy. Sea control NEVER moves land (no territory changes) — it is a parallel track. Propose at most 1-2 claims per turn and narrate each one in "events" (a "military" or "diplomatic" event).',
  isMeaningful: (data) => data.control.length > 0,
  stateFields: ['seaZones'],
  stub: () => ({ control: [] }),
  // Sea control is DURABLE (unlike the turn-transient hybrid / disasters /
  // migration layers): the user payload ALWAYS carries the current `seaZones`
  // list (even when empty) so the model knows who controls which zone.
  payload: (ctx) => ({ seaZones: ctx.seaZones ?? [] }),
 };
@@ -12,16 +12,17 @@ import type {
  IndustryProject,
  RegionResources,
  RelationStatus,
  SeaZoneClaim,
  TradeAgreement,
 } from '../../shared/types';
 import type { MarkerInfo, TurnResult, WarInfo } from '../../shared/protocol';
 /**
- * The 9 per-feature LLM abilities a turn can exercise, by the `TurnResult`
+ * The 11 per-feature LLM abilities a turn can exercise, by the `TurnResult`
 * field each one owns. This is the closed universe the ordered `ABILITIES`
 * registry (./index.ts) is built from: a turn's world changes are exactly the
 * core engine effects (events / stats / territory / no-man's-land / nation-ops
- * / markers) plus, in order, these nine abilities.
+ * / markers) plus, in order, these eleven abilities.
 */
 export type AbilityField =
  | 'takeovers'
@@ -32,7 +33,9 @@ export type AbilityField =
  | 'nuclear'
  | 'leaders'
  | 'ideology'
-  | 'disasters';
+  | 'disasters'
  | 'migration'
  | 'sea';
 /**
 * Everything a single ability's `apply` may need from the surrounding turn.
@@ -88,6 +91,7 @@ export interface UserPromptCtx {
  readonly embargoes?: Embargo[];
  readonly nationResources?: Record<string, RegionResources>;
  readonly industryProjects?: IndustryProject[];
  readonly seaZones?: SeaZoneClaim[];
 }
 /**
@@ -38,6 +38,8 @@ function makeState(id: string): GameState {
    embargoes: [],
    // (v0.36.0, #59) no industry projects.
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
 }
@@ -244,6 +246,17 @@ describe('openDb', () => {
    db.close();
  });
  it('(v0.43.0 #65) a legacy row saved before the seaZones field existed loads with it defaulted to []', () => {
    const db = openDb(':memory:');
    const legacy = makeState('legacy');
    delete (legacy as { seaZones?: unknown[] }).seaZones; // a pre-v0.43 save (field absent)
    db.save(legacy);
    const loaded = db.load('legacy');
    expect(loaded).not.toBeNull();
    expect(loaded!.seaZones).toEqual([]);
    db.close();
  });
  it('delete removes a game by id and reports absence otherwise', () => {
    const db = openDb(':memory:');
    db.save(makeState('a'));
@@ -133,6 +133,8 @@ function baseState(): GameState {
    embargoes: [],
    // (v0.36.0, #59) no industry projects on a fresh state.
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
 }
@@ -570,7 +572,7 @@ describe('validateNationOps (v0.23 #16 P4a)', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'France', to: 'French Republic' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'France', to: 'French Republic' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    });
    expect(withOps).not.toBeNull();
    expect(withOps!.nationOps).toEqual([{ kind: 'rename', nationRef: 'France', to: 'French Republic' }]);
@@ -592,7 +594,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    });
    expect(next.nations.de.name).toBe('DE'); // still the old name
    expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
@@ -613,7 +615,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'us', to: 'USA' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] }, // new proposal this turn
+      nationOps: [{ kind: 'rename', nationRef: 'us', to: 'USA' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] }, // new proposal this turn
    });
    expect(next.pendingNationOps).toEqual([
      { kind: 'rename', nationRef: 'de', to: 'Reich' }, // the old one survived
@@ -632,7 +634,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    });
    expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
  });
@@ -1089,7 +1091,7 @@ describe('applyTurnResult', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    applyTurnResult(state, result);
    expect(JSON.stringify(state)).toBe(snapshot);
@@ -1106,7 +1108,7 @@ describe('applyTurnResult', () => {
      relations: [],
      territoryChanges: [],
      unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.pending).toEqual([]);
@@ -1129,7 +1131,7 @@ describe('applyTurnResult', () => {
      // 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: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result, new Set(['wales-bbbb']));
    // the valid key was gained (taken from its sole previous owner); the bogus one was ignored
@@ -1155,7 +1157,7 @@ describe('applyTurnResult', () => {
      // released (not in state.unowned), so it does not enter GameState.unowned.
      territoryChanges: [{ nation: 'de', gain: ['POL', 'wales-bbbb'], lose: [] }],
      unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result); // no validKeys -> nothing filtered
    expect(next.nations.de.territory).toContain('wales-bbbb');
@@ -1173,7 +1175,7 @@ describe('applyTurnResult (sole-ownership invariants, v0.21 #16 P2)', () => {
    regionChanges: [],
    relations: [],
    unowned: [],
-    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
  };
  it('a double claim (two different gainers, one key) is rejected: the key stays with its original owner', () => {
@@ -1263,7 +1265,7 @@ describe('applyTurnResult (no man\'s land, v0.22 #16 P3)', () => {
    relations: [],
    territoryChanges: [],
    unowned: [],
-    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
  };
  it('a release removes the key from its sole owner and marks it in GameState.unowned', () => {
@@ -1378,7 +1380,7 @@ describe('applyTurnResult (no man\'s land, v0.22 #16 P3)', () => {
  it('a lone release is meaningful (it survives the retry/nudge path)', () => {
    expect(
-      isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: ['GBR'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] } }),
+      isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: ['GBR'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] } }),
    ).toBe(true);
  });
@@ -1685,9 +1687,9 @@ describe('buildSystemPrompt (tool mode, v0.21 #16 P2)', () => {
 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: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] } })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [{ nation: 'uk', type: 'military', title: 't', text: 'b', outcome: 'neutral' }], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] } })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] } })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] } })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] } })).toBe(false);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] } })).toBe(false);
  });
  it('(v0.23 #16 P4a) a turn that only proposes a nation-op is meaningful (it survives the retry/nudge path)', () => {
@@ -1700,7 +1702,7 @@ describe('isMeaningful', () => {
        relations: [],
        territoryChanges: [],
        unowned: [],
-        nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+        nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
      }),
    ).toBe(true);
  });
@@ -1721,7 +1723,7 @@ describe('isMeaningful', () => {
        hybrid: { ops: [] },
        economy: { trade: [], embargo: [] }, industry: { projects: [] },
        nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-        ideology: { changes: [] }, disasters: { events: [] },markers: { add: [{ type: 'city', name: 'Lyon', regionKey: 'rhone-rhne' }], remove: [] },
+        ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [{ type: 'city', name: 'Lyon', regionKey: 'rhone-rhne' }], remove: [] },
      }),
    ).toBe(true);
  });
@@ -1742,7 +1744,7 @@ describe('isMeaningful', () => {
        hybrid: { ops: [] },
        economy: { trade: [], embargo: [] }, industry: { projects: [] },
        nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-        ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+        ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
      }),
    ).toBe(true);
  });
@@ -1765,7 +1767,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.nations.de.name).toBe('The Reich');
@@ -1798,7 +1800,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.playerNationId).toBe('uk'); // player still leads it
@@ -1822,7 +1824,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    // no nation was renamed
@@ -1849,7 +1851,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    // neither was renamed (ambiguous)
@@ -1875,7 +1877,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    });
    expect(validated!.takeovers).toEqual([]);
    const next = applyTurnResult(state, validated!);
@@ -1901,7 +1903,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.nations.uk.name).toBe('The Commonwealth');
@@ -1925,7 +1927,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.version).toBe(2); // exactly one bump for the whole turn
@@ -1947,7 +1949,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    };
    const next = applyTurnResult(state, result);
    expect(next.nations.de.name).toBe('The Reich');
@@ -1981,7 +1983,7 @@ describe('markers (point placement, v0.27 #44)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [mk('city', 'Strasbourg', 'moselle-rygy')], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [mk('city', 'Strasbourg', 'moselle-rygy')], remove: [] },
    };
    const next = applyTurnResult(state, result, undefined, centroidOf);
    expect(next.markers).toHaveLength(1);
@@ -2005,13 +2007,13 @@ describe('markers (point placement, v0.27 #44)', () => {
    const add = [mk('city', 'Strasbourg', 'moselle-rygy')];
    const first = applyTurnResult(state, {
      date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add, remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add, remove: [] },
    }, undefined, centroidOf);
    expect(first.markers).toHaveLength(1);
    // a second turn proposes the exact same marker again
    const second = applyTurnResult(first, {
      date: '1939-09-05', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add, remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add, remove: [] },
    }, undefined, centroidOf);
    expect(second.markers).toHaveLength(1);
    expect(second.markers[0].id).toBe(first.markers[0].id); // stable id, no second copy
@@ -2038,7 +2040,7 @@ describe('markers (point placement, v0.27 #44)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: {
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: {
        add: [
          { type: 'city', name: 'Good', regionKey: 'moselle-rygy' }, // valid + centroid → kept
          { type: 'city', name: 'NoCent', regionKey: 'other-key' }, // in validKeys, no centroid → dropped
@@ -2085,7 +2087,7 @@ describe('markers (point placement, v0.27 #44)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: {
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: {
        add: [
          { type: 'city', name: 'NewA', regionKey: 'new-a' },
          { type: 'city', name: 'NewB', regionKey: 'new-b' },
@@ -2110,7 +2112,7 @@ describe('markers (point placement, v0.27 #44)', () => {
    ];
    const next = applyTurnResult(state, {
      date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [idA, 'zzzz-not-there'] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [idA, 'zzzz-not-there'] },
    }, undefined, centroidOf);
    expect(next.markers).toHaveLength(1);
    expect(next.markers[0].id).toBe(idB); // only A removed; the bogus id was a no-op
@@ -2126,14 +2128,14 @@ describe('markers (point placement, v0.27 #44)', () => {
    // 1) uk releases the region → the marker becomes ownerless
    const released = applyTurnResult(state, {
      date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: ['moselle-rygy'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      unowned: ['moselle-rygy'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    }, undefined, centroidOf);
    expect(released.markers[0].ownerNationId).toBeNull();
    // 2) de re-claims the region → the marker's owner follows to de
    const reclaimed = applyTurnResult(released, {
      date: '1939-09-05', events: [], stateChanges: [], regionChanges: [], relations: [],
      territoryChanges: [{ nation: 'de', gain: ['moselle-rygy'], lose: [] }],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, industry: { projects: [] }, nuclear: { arm: [], strikes: [] }, leaders: { changes: [] }, ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    }, undefined, centroidOf);
    expect(reclaimed.markers[0].ownerNationId).toBe('de');
  });
@@ -2203,7 +2205,7 @@ describe('markers (point placement, v0.27 #44)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [{ type: 'city', name: 'Strasbourg', regionKey: 'moselle-rygy' }], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [{ type: 'city', name: 'Strasbourg', regionKey: 'moselle-rygy' }], remove: [] },
    });
    const { state } = await runTurn({
      llm: fakeLlm([result]),
@@ -2278,6 +2280,8 @@ function mkTurnState(
    embargoes: [],
    // (v0.36.0, #59) no industry projects on a fresh state.
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
 }
@@ -2300,6 +2304,8 @@ function mkTurnResult(partial: Partial<TurnResult>): TurnResult {
    leaders: partial.leaders ?? { changes: [] },
    ideology: partial.ideology ?? { changes: [] },
    disasters: partial.disasters ?? { events: [] },
    migration: partial.migration ?? { ops: [] },
    sea: partial.sea ?? { control: [] },
    markers: partial.markers ?? { add: [], remove: [] },
  };
 }
@@ -3025,7 +3031,7 @@ describe('validateTakeovers (v0.32.0 #54)', () => {
      hybrid: { ops: [] },
      economy: { trade: [], embargo: [] }, industry: { projects: [] },
      nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-      ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+      ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
    });
    expect(withTakeovers).not.toBeNull();
    // the valid one survives, the empty-name one is dropped
@@ -3413,7 +3419,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
        hybrid: { ops: [] },
        economy: { trade: [], embargo: [] }, industry: { projects: [] },
        nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-        ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+        ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
      }),
    ).toBe(true);
  });
@@ -3434,7 +3440,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
        hybrid: { ops: [] },
        economy: { trade: [], embargo: [] }, industry: { projects: [] },
        nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-        ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+        ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
      }),
    ).toBe(true);
  });
@@ -3455,7 +3461,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
        hybrid: { ops: [] },
        economy: { trade: [], embargo: [] }, industry: { projects: [] },
        nuclear: { arm: [], strikes: [] }, leaders: { changes: [] },
-        ideology: { changes: [] }, disasters: { events: [] },markers: { add: [], remove: [] },
+        ideology: { changes: [] }, disasters: { events: [] }, migration: { ops: [] }, sea: { control: [] }, markers: { add: [], remove: [] },
      }),
    ).toBe(false);
  });
@@ -16,6 +16,7 @@ import type {
  RegionResources,
  RegionStats,
  RoundItem,
  SeaZoneClaim,
  StatKey,
  TradeAgreement,
 } from '../shared/types';
@@ -94,6 +95,24 @@ export {
  DISASTER_TYPES,
  DISASTER_SEVERITIES,
  DISASTER_EFFECTS,
  validateMigrationOps,
  applyMigrationOp,
  shiftRelationTowardPositive,
  isMigrationKind,
  isMigrationScale,
  MIGRATION_KINDS,
  MIGRATION_SCALES,
  MIGRATION_SOURCE_EFFECTS,
  MIGRATION_DESTINATION_EFFECTS,
  LARGE_INFLUX_STABILITY_DIP,
  validateSeaOps,
  applySeaControl,
  applySeaZoneBonuses,
  SEA_ZONE_BONUS,
  SEA_ZONES,
  SEA_ZONE_IDS,
  isSeaZoneId,
  seaZoneName,
 } from './abilities';
 // --- The LLM's getNeighbours tool (v0.21, #16 P2: contiguous region transfers) ---
@@ -366,6 +385,14 @@ export function buildUserPrompt(
   * key on any nation) when undefined.
   */
  nuclear?: Record<string, boolean>,
  /**
   * (v0.43.0, #65) The game's current sea-zone control (each a `{ zone, by }`
   * pair of the fixed sea zones and their controlling nation id). Emitted
   * verbatim (even when empty) so the model knows which of the 12 fixed sea
   * zones each nation currently controls and can re-claim or contest them via
   * `TurnResult.sea`. Omitted entirely when undefined.
   */
  seaZones?: SeaZoneClaim[],
 ): string {
  const player = state.nations[state.playerNationId];
  const playerName = player?.name ?? state.playerNationId;
@@ -475,6 +502,7 @@ export function buildUserPrompt(
    embargoes,
    nationResources,
    industryProjects,
    seaZones,
  };
  Object.assign(payload, ABILITIES[0].payload(upCtx)); // takeovers → takeoverRisks
  if (noMansLand !== undefined) payload.unowned = noMansLand;
@@ -483,6 +511,7 @@ export function buildUserPrompt(
  Object.assign(payload, ABILITIES[2].payload(upCtx)); // hybrid → relations
  Object.assign(payload, ABILITIES[3].payload(upCtx)); // economy → trades, embargoes
  Object.assign(payload, ABILITIES[4].payload(upCtx)); // industry → resources, industry
  Object.assign(payload, ABILITIES[10].payload(upCtx)); // sea → seaZones (always emitted)
  return JSON.stringify(payload, null, 2);
 }
@@ -622,6 +651,8 @@ export function validateTurnResult(
    leaders: { changes: [] },
    ideology: { changes: [] },
    disasters: { events: [] },
    migration: { ops: [] },
    sea: { control: [] },
    markers: { add: [], remove: [] },
  };
@@ -712,7 +743,7 @@ export function validateTurnResult(
  // list for the player to confirm/reject.
  result.nationOps = validateNationOps(o.nationOps);
-  // The 9 per-feature LLM abilities (v0.40.0, #67): each one's validate call
+  // The 11 per-feature LLM abilities (v0.40.0, #67): each one's validate call
  // is owned by its Ability module in the ABILITIES registry. The field's raw
  // value is passed through a.validate() which returns the validated field shape.
  for (const a of ABILITIES) {
@@ -906,6 +937,9 @@ export function applyTurnResult(
  // (v0.36, #59) active industry projects; a legacy/corrupt clone without the
  // field starts empty (the turn then only ever adds to it).
  next.industry = next.industry ?? [];
  // (v0.43.0, #65) sea-zone control; a legacy/corrupt clone without the field
  // starts empty (the turn then upserts this turn's claims into it).
  next.seaZones = next.seaZones ?? [];
  const actingTurn = state.turn; // this action resolves the current turn
  next.turn = state.turn + 1; // then we advance to the next turn to play
  next.date = isDateLike(result.date) ? result.date : addDays(state.date, 2);
@@ -1583,6 +1617,9 @@ export async function runTurn(opts: {
    state.industry ?? [],
    // (v0.37.0, #60) per-nation nuclear capability (flag or rocket marker).
    nuclearCapability,
    // (v0.43.0, #65) the current sea-zone control (always emitted — even when
    // empty — so the model knows who controls which of the fixed sea zones).
    state.seaZones ?? [],
  );
  const nudge =
    'Your previous output was invalid. Respond with ONLY the JSON object described above for this batch — no prose, no fences.';
@@ -190,6 +190,8 @@ app.post('/api/games', (req: Request, res) => {
    // declares them over time via TurnResult.industry (one per region, a
    // per-region SET).
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
  // 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
@@ -59,6 +59,8 @@ const state: GameState = {
  embargoes: [],
  // (v0.36.0, #59) the map is ownership-only; industry is unused here.
  industry: [],
  // (v0.43.0, #65) no sea-zone control on a fresh state.
  seaZones: [],
 };
 // The RegionMap built from the fixture: the authoritative region key → owner source.
@@ -48,6 +48,8 @@ function mkState(
    trades: [],
    embargoes: [],
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
  if (regionStats !== undefined) base.regionStats = regionStats as GameState['regionStats'];
  else delete (base as { regionStats?: unknown }).regionStats; // simulate a legacy row
@@ -118,6 +118,8 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
      embargoes: [],
      // (v0.36.0, #59) unused here (allTerritoryKeys is ownership-only).
      industry: [],
      // (v0.43.0, #65) no sea-zone control on a fresh state.
      seaZones: [],
    };
    // 16 GBR sub-regions + 42 FRA sub-regions, no overlap between the two.
    expect(allTerritoryKeys(state).size).toBe(58);
@@ -100,6 +100,14 @@ export interface StubPayload {
   * deterministicTurn), so the industry path is covered by unit tests only.
   */
  industry?: Array<{ regionKey: string; type: string }>;
  /**
   * (v0.43.0, #65) The currently active sea-zone control
   * (`{ zone, by }` — fixed sea-zone id + controlling nation id), emitted by
   * the engine's user prompt (always, even when empty). The stub ignores this
   * field — it never claims, contests or re-claims a sea zone (see
   * deterministicTurn), so the sea path is covered by unit tests only.
   */
  seaZones?: Array<{ zone: string; by: string }>;
 }
 function truncate(s: string, n: number): string {
@@ -173,6 +181,18 @@ function truncate(s: string, n: number): string {
 * (v0.39.0, #62) The stub likewise NEVER changes a nation's ideology (it
 * always returns `ideology: { changes: [] }`) — the ideology path is covered
 * by unit tests only, keeping the e2e assertions untouched.
 *
 * (v0.41.0, #63) The stub likewise NEVER declares a disaster or pandemic (it
 * always returns `disasters: { events: [] }`) — the disasters path is covered
 * by unit tests only, keeping the e2e assertions untouched.
 *
 * (v0.42.0, #64) The stub likewise NEVER declares a migration / refugee flow
 * (it always returns `migration: { ops: [] }`) — the migration path is
 * covered by unit tests only, keeping the e2e assertions untouched.
 *
 * (v0.43.0, #65) The stub likewise NEVER claims, contests or re-claims a sea
 * zone (it always returns `sea: { control: [] }`) — the sea-control path is
 * covered by unit tests only, keeping the e2e assertions untouched.
 */
 export function deterministicTurn(p: StubPayload): TurnResult {
  const state = p.state;
@@ -252,13 +272,13 @@ export function deterministicTurn(p: StubPayload): TurnResult {
    nationOps: [], // the stub never proposes nation ops (see doc comment)
  };
-  // The 9 ability fields, filled by the registry in its canonical order. The
+  // The 11 ability fields, filled by the registry in its canonical order. The
  // stub is ability-inert: every ability contributes its own no-op default
  // (each ability's `stub()` — see the per-ability doc comments above), so the
  // e2e assertions are unaffected. The insertion order here (ABILITIES) is the
  // historical key order pinned by the stub's deterministic output
  // (takeovers → wars → hybrid → economy → industry → nuclear → leaders →
-  // ideology → disasters), which must stay byte-identical.
+  // ideology → disasters → migration → sea), which must stay byte-identical.
  const abilities = {} as Record<AbilityField, unknown>;
  for (const a of ABILITIES) abilities[a.field] = a.stub();
@@ -650,6 +650,139 @@ export interface DisastersOps {
  events: DisasterEvent[];
 }
 // --- Migration & refugees (v0.42.0, #64) --------------------------------------
 //
 // People moving between nations each turn: ordinary migration, refugee flows
 // (fleeing a war or disaster), a spreading diaspora, and an exodus (people
 // leaving with no destination). Each op names a `kind`, a source `from` (the
 // nation people leave), a destination `to` (required for every kind except
 // `exodus`), and a `scale` (small / moderate / large). The engine applies a
 // DETERMINISTIC effect chosen from the per-`scale` tables
 // `MIGRATION_SOURCE_EFFECTS` / `MIGRATION_DESTINATION_EFFECTS` (defined in
 // `server/abilities/migration.ts`) — no hidden randomness: the LLM chooses the
 // kind and scale, the tables decide the magnitude. The source LOSES a small
 // amount of population and economy, the destination GAINS a small amount of
 // population and economy (a `large` influx additionally strains the
 // destination's stability), both clamped to 0–100, mirrored to each side's
 // regions (`regionStats`), and each side's derived `stats` re-derived
 // afterwards (the same 0-region / no-entry guards as the hybrid / economy /
 // disasters layers). The from↔to relation moves one step toward the positive
 // end of the ally/neutral/rival/hostile ladder (`shiftRelationTowardPositive`)
 // — capped at `ally` for `refugees`, `neutral` for `migration` / `diaspora`,
 // and not at all for `exodus` — and a `war` relation is never touched. It is
 // **turn-transient** like the hybrid / disasters layers: there is NO `GameState`
 // field, no durable list, and no `db.ts` change — a continuing flow is simply
 // re-declared each turn it persists. It never moves territory (sole ownership
 // is untouched) and never creates or escalates a war.
 /** The kind of population flow a migration op describes (v0.42.0, #64). */
 export type MigrationKind = 'migration' | 'refugees' | 'diaspora' | 'exodus';
 /** The size of a migration flow (v0.42.0, #64). */
 export type MigrationScale = 'small' | 'moderate' | 'large';
 /**
 * A single migration / refugee flow (v0.42.0, #64): the `kind`, the source
 * `from` (a nation id / name — the nation people leave), the destination `to`
 * (a nation id / name — required for every kind except `exodus`, which has no
 * destination), the `scale`, and an optional short `detail`. The deterministic
 * stat effects are looked up from `MIGRATION_SOURCE_EFFECTS` /
 * `MIGRATION_DESTINATION_EFFECTS` by `scale`.
 */
 export interface MigrationOp {
  /** The kind of flow (one of {@link MigrationKind}). */
  kind: MigrationKind;
  /** The source nation (by id or name) people leave. */
  from: string;
  /** The destination nation (by id or name). Required for every kind except `exodus`. */
  to?: string;
  /** How many people moved (one of {@link MigrationScale}). */
  scale: MigrationScale;
  /** Optional short annotation (≤300 chars). */
  detail?: string;
 }
 /** The migration block of a `TurnResult`. Required; default `{ ops: [] }`. */
 export interface MigrationOps {
  ops: MigrationOp[];
 }
 // ---------------------------------------------------------------------------
 // (v0.43.0, #65) Sea zones & sea control — the naval layer, fully parallel to
 // but INDEPENDENT of land. The world has a fixed set of 12 named SEA ZONES
 // ({@link SEA_ZONES}); each is under the SOLE CONTROL of at most one nation.
 // Controlling a sea zone never moves land (`territory` / `unowned` are
 // untouched) and moving land never touches a sea zone. `SeaZoneClaim` (the
 // durable per-zone record, `{ zone, by }`) lives in `shared/types.ts` like
 // `Trade` / `Embargo` / `War` / `IndustryProject`; `GameState.seaZones` is a
 // list of them, unique per zone (`[]` at creation; a legacy SQLite row
 // without the field loads as `[]` — additive, never wiped). Each turn the LLM
 // declares `TurnResult.sea.control` ops — one op names the zone and the
 // nation that (now) controls it. The engine resolves `by` (id first, then a
 // case-insensitive unique name) and UPSERTS the zone's claim (replace in
 // place if the zone is already claimed, append if new). If two or more ops
 // this turn claim the SAME zone for DIFFERENT resolved nations, the zone is
 // CONTESTED: the higher current `stats.military` wins (a tie goes to the op
 // listed earlier in the `control` array) — deterministic, no hidden
 // randomness; an unresolvable `by` is dropped (never thrown). Every committed
 // turn — including a turn with an empty `control` — each existing claim's
 // controller earns a small DETERMINISTIC bonus (`SEA_ZONE_BONUS = 1` military
 // + 1 economy, clamped to 0–100, mirrored to the controller's regions and
 // re-derived with the same 0-region / no-entry guards as the economy /
 // migration layers); a claim whose nation no longer exists is skipped (the
 // claim is kept, never thrown). The layer is DURABLE (unlike the turn-
 // transient hybrid / disasters / migration layers): `GameState.seaZones`
 // persists across turns and in SQLite. The user payload carries the current
 // `seaZones` list so the model knows who controls which zone.
 /** The 12 named sea zones the world model knows (v0.43.0, #65). */
 export const SEA_ZONES = [
  { id: 'north-atlantic', name: 'North Atlantic' },
  { id: 'south-atlantic', name: 'South Atlantic' },
  { id: 'pacific', name: 'Pacific Ocean' },
  { id: 'indian', name: 'Indian Ocean' },
  { id: 'mediterranean', name: 'Mediterranean Sea' },
  { id: 'north-sea', name: 'North Sea' },
  { id: 'baltic', name: 'Baltic Sea' },
  { id: 'arctic', name: 'Arctic Ocean' },
  { id: 'black-sea', name: 'Black Sea' },
  { id: 'gulf-mexico', name: 'Gulf of Mexico' },
  { id: 'red-sea', name: 'Red Sea' },
  { id: 'sargasso', name: 'Sargasso Sea' },
 ] as const;
 /** The set of valid sea-zone ids (v0.43.0, #65). */
 export const SEA_ZONE_IDS: ReadonlySet<string> = new Set(SEA_ZONES.map((z) => z.id));
 /** Whether `id` is one of the fixed sea-zone ids (v0.43.0, #65). */
 export function isSeaZoneId(id: string): boolean {
  return SEA_ZONE_IDS.has(id);
 }
 /** The display name of a sea-zone id; an unknown id is returned as-is (v0.43.0, #65). */
 export function seaZoneName(id: string): string {
  return SEA_ZONES.find((z) => z.id === id)?.name ?? id;
 }
 /**
 * A single sea-control op (v0.43.0, #65): `zone` is one of the fixed
 * {@link SEA_ZONES} ids and `by` is the nation that (now) controls it (by id
 * or name). One op SETS or REPLACES the zone's controller; two or more ops on
 * the same zone for different nations are CONTESTED — the higher current
 * `stats.military` wins (a tie: the earlier-listed op).
 */
 export interface SeaControlOp {
  /** The sea zone (one of {@link SEA_ZONE_IDS}). */
  zone: string;
  /** The controlling nation (by id or name). */
  by: string;
 }
 /** The sea-control block of a `TurnResult`. Required; default `{ control: [] }`. */
 export interface SeaOps {
  control: SeaControlOp[];
 }
 /** The exact JSON object the world-simulator LLM must return for a turn. */
 export interface TurnResult {
  date: string;
@@ -819,6 +952,46 @@ export interface TurnResult {
   * `{ events: [] }`.
   */
  disasters: DisastersOps;
  /**
   * (v0.42.0, #64) Migration & refugee flows this turn — people moving between
   * nations: ordinary `migration`, `refugees` fleeing a war or disaster, a
   * spreading `diaspora`, and an `exodus` (people leaving with no destination).
   * Each op names a `from` (the source nation, by id or name) and, for every
   * kind except `exodus`, a `to` (the destination nation, by id or name), plus
   * a `scale` (small / moderate / large). Applied directly by `applyTurnResult`
   * (like the disasters / hybrid layers): the source LOSES a small amount of
   * population and economy, the destination GAINS a small amount of population
   * and economy (a `large` influx additionally strains the destination's
   * stability by 2), both clamped to 0–100, mirrored to each side's regions,
   * and each side's derived `stats` re-derived afterwards; the from↔to
   * relation moves one step toward the positive end of the
   * ally/neutral/rival/hostile ladder (capped at `ally` for `refugees`,
   * `neutral` for `migration` / `diaspora`, not at all for `exodus`; a `war`
   * relation is never touched). The layer is turn-transient (no `GameState`
   * field, no `db.ts` change) — a continuing flow is simply re-declared each
   * turn it persists. It never moves borders (sole ownership is untouched) and
   * never creates or escalates a war. At most 1–2 per turn, each narrated in
   * `events` (a `social` or `diplomatic` event). Required; default
   * `{ ops: [] }`.
   */
  migration: MigrationOps;
  /**
   * (v0.43.0, #65) Sea-zone control ops this turn — the naval layer, fully
   * parallel to but INDEPENDENT of land: each op names one of the 12 fixed
   * sea zones (`SEA_ZONES`) and the nation that now controls it. The engine
   * resolves `by` (id first, then a case-insensitive unique name) and
   * upserts the zone's claim in `GameState.seaZones` (a single op sets or
   * replaces the controller; two or more ops on the same zone for different
   * nations are CONTESTED — the higher current `stats.military` wins, a tie
   * goes to the op listed earlier in `control`; an unresolvable `by` is
   * dropped, never thrown). Every committed turn, each existing claim's
   * controller earns a small deterministic military/economy bonus
   * (`SEA_ZONE_BONUS`). Sea control never moves land: `territory` and
   * `unowned` are untouched. At most 1–2 per turn, each narrated in `events`
   * (a `military` or `diplomatic` event). Required; default
   * `{ control: [] }`.
   */
  sea: SeaOps;
  /**
   * (v0.27, #44) Map-marker ops this turn. `add` places new named markers
   * (the engine positions each at its region's centroid + a small
@@ -461,6 +461,8 @@ export function worldDraftToGameState(
    embargoes: [],
    // (v0.36, #59) No industry projects on a fresh (dynamic) game.
    industry: [],
    // (v0.43.0, #65) no sea-zone control on a fresh state.
    seaZones: [],
  };
  return state;
 }
@@ -249,6 +249,23 @@ export interface IndustryProject {
  type: IndustryType;
 }
 /**
 * (v0.43.0, #65) One sea-zone claim: which nation controls one of the fixed
 * sea zones (see `SEA_ZONES` in `shared/protocol.ts`). The world keeps at
 * most ONE claim per zone — a new op on an already-claimed zone REPLACES the
 * controller in place (the zone's entry is updated, never duplicated), and if
 * a turn declares the same zone for two different resolved nations the higher
 * current `stats.military` wins (a tie: the op listed earlier in the turn's
 * `control` array). Sea control is fully parallel to but INDEPENDENT of land:
 * it never touches `territory` / `unowned`.
 */
 export interface SeaZoneClaim {
  /** The sea zone (one of `SEA_ZONE_IDS`). */
  zone: string;
  /** The id of the nation that controls it (resolved, not a name). */
  by: string;
 }
 /**
 * (v0.33.0, #56) A first-class **war** — a named, ongoing armed conflict
 * between two or more nations. Unlike the boolean `war` relation (which a
@@ -443,6 +460,20 @@ export interface GameState {
   * with this defaulted to `[]` (see server/db.ts) — additive, no data wipe.
   */
  industry: IndustryProject[];
  /**
   * (v0.43.0, #65) Sea-zone control (see {@link SeaZoneClaim}): one entry per
   * controlled sea zone — which of the 12 fixed zones (`SEA_ZONES`) each
   * nation controls. At most ONE entry per zone (unique by `zone`); a turn's
   * `sea.control` ops upsert entries (a re-claim by a different nation
   * replaces the controller in place; a same-zone contest goes to the higher
   * current `stats.military`, a tie to the earlier-listed op). Every
   * committed turn each claim's controller earns a small deterministic
   * military/economy bonus (`SEA_ZONE_BONUS`). Sea control never moves land
   * (`territory` / `unowned` are untouched). Always `[]` on a fresh game;
   * rows saved before v0.43 load with this defaulted to `[]` (see
   * server/db.ts) — additive, no data wipe.
   */
  seaZones: SeaZoneClaim[];
 }
 /**