feat(#56): War as a first-class state — declare/end ops, mutual-defense drag-in, relation sync

Promote the bare 'war' relation to a named War entity in GameState.wars:
- War: { id, sides[], declaredTurn, declaredDate?, aims?, status, front? }
- TurnResult.wars: { declare: WarDeclareOp[], end: WarEndOp[] }
- syncWarRelations: derive 'war' from active wars, fallback to 'hostile' on end
- Mutual-defense drag-in: belligerent allies added to sides (one level)
- Bare 'war' back-compat: never downgraded, never force-created
- Stub: empty wars (e2e unaffected); ~30 new unit tests

v0.33.0

shared/protocol.ts

@@ -51,6 +51,50 @@ export interface TerritoryChange {
   lose: string[];
 }
 
+// --- Wars (v0.33.0, #56): first-class war entities --------------------------
+//
+// A war is an explicit world entity (see types.War), not just a boolean
+// relation: the LLM DECLARES one (it becomes an active War with an engine-
+// assigned stable id) and later ENDS one by id. The engine derives the
+// symmetric `war` relation from the set of ACTIVE wars on every turn (two
+// nations are in a `war` relation iff they are both belligerents of at least
+// one active war) and downgrades it to `hostile` when the war ends — so the
+// relation can never drift apart from the war state.
+
+/**
+ * (v0.33.0, #56) Declare a new war this turn. `sides` names every
+ * belligerent (≥2 distinct nation ids — each resolved by `resolveNationRef`,
+ * so a unique name also works); any two distinct sides end the turn in a
+ * `war` relation. `aims` are optional short war aims for the narrative. The
+ * engine assigns the stable id, the declared turn/date, drags in the
+ * mutual-defense allies of each belligerent, and drops the op when fewer than
+ * two sides resolve (never throws).
+ */
+export interface WarDeclareOp {
+  /** The belligerent nations (≥2 distinct ids or unique names). */
+  sides: string[];
+  /** Optional short war aims (narrative only). */
+  aims?: string[];
+}
+
+/**
+ * (v0.33.0, #56) End an existing ACTIVE war this turn, by its stable id
+ * (the model sees the current active wars in the user payload's `wars`
+ * field). `outcome` is `armistice` (a negotiated stop) or `capitulation`
+ * (one side surrenders); the war keeps its id/sides and stays in
+ * `GameState.wars` as history with that final status. `terms` are optional
+ * short peace terms (narrative only — the model narrates the details in
+ * `events`). An unknown id, or a war that is already ended, is a no-op
+ * (never throws).
+ */
+export interface WarEndOp {
+  /** The stable id of the active war to end (from the user payload). */
+  id: string;
+  outcome: 'armistice' | 'capitulation';
+  /** Optional short peace terms (narrative only). */
+  terms?: string;
+}
+
 // --- Nation-management ops (v0.23 P4a / v0.24 P4b, #16: the hybrid "LLM
 // proposes, player confirms" model) ------------------------------------------
 //
@@ -189,6 +233,19 @@ export interface MarkerInfo {
   owner: string | null;
 }
 
+/**
+ * (v0.33.0, #56) One ACTIVE war as the user prompt presents it to the model
+ * (the `wars` field): its stable `id` (the model echoes it in
+ * `TurnResult.wars.end` to end it), its belligerent `sides`, and optional
+ * short `aims`. Ended wars are NOT included — they stay in `GameState.wars`
+ * as history, but the model only needs to address the active ones.
+ */
+export interface WarInfo {
+  id: string;
+  sides: string[];
+  aims?: string[];
+}
+
 /**
  * The per-type presentation of a marker: its display label (tooltip /
  * dossier), its color, and its glyph character (a symbol-layer text label —
@@ -297,6 +354,19 @@ export interface TurnResult {
    * (default `[]`).
    */
   takeovers: Takeover[];
+  /**
+   * (v0.33.0, #56) First-class war ops this turn. `declare` starts new wars
+   * (≥2 distinct belligerents; the engine assigns the stable id / declared
+   * turn / date, drags in the mutual-defense allies of each belligerent, and
+   * derives the `war` relation between every pair of sides); `end` closes an
+   * existing ACTIVE war by id (`armistice` = a negotiated stop,
+   * `capitulation` = one side surrenders), which downgrades the relation the
+   * war had derived back to `hostile`. Both sub-fields are required and
+   * default `[]`; a turn with war activity is meaningful (it survives the
+   * retry/nudge path). The model sees the current active wars (id + sides +
+   * aims) in the user payload's `wars` field, so it can `end` by id.
+   */
+  wars: { declare: WarDeclareOp[]; end: WarEndOp[] };
   /**
    * (v0.27, #44) Map-marker ops this turn. `add` places new named markers
    * (the engine positions each at its region's centroid + a small

shared/scenario.ts

@@ -453,6 +453,9 @@ export function worldDraftToGameState(
     // Seed AFTER the territories hold real region keys: each owned region gets
     // a copy of its owner's stats, so the derived aggregate equals them.
     regionStats: seedRegionStats(nations),
+    // (v0.33.0, #56) No wars on a fresh (dynamic) game; any preset-level `war`
+    // relation stays a bare/implicit one, not an entity (see syncWarRelations).
+    wars: [],
   };
   return state;
 }

shared/types.ts

@@ -143,6 +143,44 @@ export interface MapMarker {
   placedTurn: number;
 }
 
+/**
+ * (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
+ * preset or a bare `relations` entry can carry without any structure behind
+ * it), a `War` is an explicit world entity the engine tracks: the LLM
+ * declares it (a turn's `wars.declare`), the engine assigns it a stable id
+ * (`w1`, `w2`, …), the turn and in-game date it was declared, and it stays in
+ * `GameState.wars` for the rest of the game as history after it ends.
+ *
+ * **Semantics of `sides`:** the flat list of every belligerent in the war
+ * (≥2 distinct nation ids). Any two distinct members of an active war's
+ * sides are at war with each other — the engine derives the symmetric `war`
+ * relation for every such pair on every turn (see the engine's
+ * `syncWarRelations`), and downgrades the relation to `hostile` when the war
+ * ends. A mutual-defense ally of a belligerent is dragged into the same list
+ * on declaration (the engine does this automatically).
+ */
+export interface War {
+  /** Stable id (`w1`, `w2`, …) assigned by the engine on declaration. */
+  id: string;
+  /** The belligerent nations (≥2 distinct ids; see the note above). */
+  sides: string[];
+  /** The turn number the war was declared on. */
+  declaredTurn: number;
+  /** The in-game date the war took effect on (`YYYY-MM-DD`). */
+  declaredDate?: string;
+  /** Optional short war aims the LLM names at declaration. */
+  aims?: string[];
+  /**
+   * Lifecycle: `active` until a turn ends the war, then the end outcome —
+   * `armistice` (a negotiated stop) or `capitulation` (one side surrenders) —
+   * or the generic `ended`. Ended wars stay in `GameState.wars` as history.
+   */
+  status: 'active' | 'armistice' | 'capitulation' | 'ended';
+  /** Optional region keys the war's front line runs through (reserved). */
+  front?: string[];
+}
+
 /** A narrative event the simulation emitted on some turn. */
 export interface EventEntry {
   id: string;
@@ -251,6 +289,20 @@ export interface GameState {
    * — additive, no data wipe.
    */
   regionStats: Record<string, RegionStats>;
+  /**
+   * (v0.33.0, #56) First-class war entities (see {@link War}): declared by a
+   * turn's `wars.declare` (the engine assigns the id, declared turn/date, and
+   * drags in mutual-defense allies) and closed by `wars.end` (armistice /
+   * capitulation). The engine DERIVES the `war` relation from the ACTIVE
+   * wars on every turn (two nations are in a `war` relation iff they are both
+   * belligerents of ≥1 active war), so the boolean relation and the war
+   * entities can never drift apart. A bare preset `war` relation with no
+   * active war behind it stays as-is (an implicit, unnamed war — never
+   * force-created into an entity). Always `[]` on a fresh game; rows saved
+   * before v0.33 load with this defaulted to `[]` (see server/db.ts) —
+   * additive, no data wipe.
+   */
+  wars: War[];
 }
 
 /**