fix: game end condition not triggering when last player remains

src/engine/systems/GameStateSystem.ts

@@ -204,16 +204,13 @@ export class GameStateSystem extends System {
     // Skip victory conditions in battle simulator mode
     if (isBattleSimulatorMode()) return;
 
-    const players = new Set<string>();
+    // Use the stable set of game participants (from game setup), not current entities.
+    // Entity-based counting is unreliable: buildings are immediately destroyed on death,
+    // so eliminated players with no surviving units would disappear from entity queries,
+    // causing players.size to drop to 1 and preventing victory from ever being declared.
+    const players = new Set<string>(this.playerTeams.keys());
     const playersWithBuildings = new Set<string>();
 
-    // Collect all players
-    const allEntities = this.world.getEntitiesWith('Selectable');
-    for (const entity of allEntities) {
-      const selectable = entity.get<Selectable>('Selectable')!;
-      players.add(selectable.playerId);
-    }
-
     // Check which players still have complete buildings (not blueprints)
     const buildings = this.world.getEntitiesWith('Building', 'Selectable', 'Health');
     for (const entity of buildings) {
@@ -290,14 +287,10 @@ export class GameStateSystem extends System {
   }
 
   private handleSurrender(playerId: string): void {
-    const players = new Set<string>();
-    const allEntities = this.world.getEntitiesWith('Selectable');
-    for (const entity of allEntities) {
-      const selectable = entity.get<Selectable>('Selectable')!;
-      players.add(selectable.playerId);
-    }
-
-    const remainingPlayers = [...players].filter((p) => p !== playerId);
+    const players = new Set<string>(this.playerTeams.keys());
+    const remainingPlayers = [...players].filter(
+      (p) => p !== playerId && !this.eliminatedPlayers.has(p)
+    );
     if (remainingPlayers.length === 1) {
       this.declareVictory(remainingPlayers[0], playerId, 'surrender');
     }

src/engine/systems/ai/AICoordinator.ts

@@ -317,6 +317,9 @@ export class AICoordinator extends System {
   /** Reactive defense tick tracking per player */
   private lastReactiveDefenseTick: Map<string, number> = new Map();
 
+  /** Players eliminated from the game (lost all buildings) - stop AI operations */
+  private eliminatedPlayers: Set<string> = new Set();
+
   // Subsystems
   private economyManager: AIEconomyManager;
   private buildOrderExecutor: AIBuildOrderExecutor;
@@ -400,6 +403,14 @@ export class AICoordinator extends System {
       }
     );
 
+    // Stop AI operations for eliminated players
+    this.game.eventBus.on('game:playerEliminated', (data: { playerId: string }) => {
+      if (this.aiPlayers.has(data.playerId)) {
+        this.eliminatedPlayers.add(data.playerId);
+        debugAI.log(`[AICoordinator] ${data.playerId} eliminated - AI operations stopped`);
+      }
+    });
+
     // Track research completion
     this.game.eventBus.on(
       'research:complete',
@@ -1236,6 +1247,7 @@ export class AICoordinator extends System {
     // This ensures defense response isn't gated by the 40-tick medium delay
     if (currentTick % 10 === 0) {
       for (const [, ai] of this.aiPlayers) {
+        if (this.eliminatedPlayers.has(ai.playerId)) continue;
         if (this.tacticsManager.isUnderAttack(ai)) {
           if (ai.state === 'attacking' && ai.activeAttackOperation) {
             // During active attacks, trigger reactive defense for home units
@@ -1250,6 +1262,9 @@ export class AICoordinator extends System {
     }
 
     for (const [playerId, ai] of this.aiPlayers) {
+      // Skip eliminated players - their units become inert
+      if (this.eliminatedPlayers.has(playerId)) continue;
+
       const actionDelay = this.getActionDelay(ai.difficulty);
       if (currentTick - ai.lastActionTick < actionDelay) continue;