feat: wire backstory generation into NPC spawn flow

Trigger fire-and-forget backstory generation whenever an NPC spawns,
both during initial spawn and via player spawn-npc requests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/game/GameLoop.ts

@@ -11,6 +11,7 @@ import { relationshipSystem } from '../systems/relationshipSystem.js';
 import { createBondRegistry } from '../systems/bondRegistry.js';
 import { spawnNPC } from './spawner.js';
 import { createLlmService, type LlmService } from '../llm/llmService.js';
+import { generateBackstory } from '../llm/backstoryGenerator.js';
 
 export class GameLoop {
   readonly world: World;
@@ -47,9 +48,14 @@ export class GameLoop {
     }
   }
 
+  generateNpcBackstory(entityId: number): void {
+    generateBackstory(this.world, entityId, this.llmService);
+  }
+
   private spawnInitialNPCs(count: number): void {
     for (let i = 0; i < count; i++) {
-      spawnNPC(this.world, this.map);
+      const entity = spawnNPC(this.world, this.map);
+      this.generateNpcBackstory(entity);
     }
   }
 

server/src/network/SocketServer.ts

@@ -70,7 +70,8 @@ export class SocketServer {
 
         const target = map.findNearestWalkable(data.x, data.y, 3)
           ?? map.getRandomWalkable();
-        spawnNPC(world, map, target);
+        const npcEntity = spawnNPC(world, map, target);
+        this.gameLoop.generateNpcBackstory(npcEntity);
       });
 
       // Handle superlatives subscription