feat: wire socialSystem into game loop, spawner, and state serializer

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

server/src/network/stateSerializer.ts

@@ -1,12 +1,13 @@
 import type {
   EntityState, WorldState, StateUpdate,
-  Position, Movement, Appearance, Needs, NPCBrain, PlayerControlled,
+  Position, Movement, Appearance, Needs, NPCBrain, PlayerControlled, SocialState,
 } from '@dflike/shared';
 import { TILE_SIZE } from '@dflike/shared';
 import type { World } from '../ecs/World.js';
 import type { GameMap } from '../map/GameMap.js';
 
 export function serializeEntity(world: World, entityId: number): EntityState {
+  const socialState = world.getComponent<SocialState>(entityId, 'socialState');
   return {
     id: entityId,
     position: world.getComponent<Position>(entityId, 'position')!,
@@ -16,6 +17,11 @@ export function serializeEntity(world: World, entityId: number): EntityState {
     npcBrain: world.getComponent<NPCBrain>(entityId, 'npcBrain'),
     playerControlled: world.getComponent<PlayerControlled>(entityId, 'playerControlled'),
     name: world.getComponent<string>(entityId, 'name'),
+    socialState: socialState ? {
+      phase: socialState.phase,
+      partnerId: socialState.partnerId,
+      outcome: socialState.outcome,
+    } : undefined,
   };
 }