feat(game): 添加开会暂停系统——点击开会按钮暂停游戏，可安心发激励，结束开会后恢复

game/GameManager.ts

@@ -102,6 +102,22 @@ export class GameManager {
     this.onKPIChange.forEach(cb => cb(this.kpi))
   }
 
+  /** 暂停游戏（仅 playing 状态下有效） */
+  pause(): boolean {
+    if (this.gameState !== 'playing') return false
+    this.gameState = 'paused'
+    return true
+  }
+
+  /** 恢复游戏（仅 paused 状态下有效） */
+  resume(): boolean {
+    if (this.gameState !== 'paused') return false
+    this.gameState = 'playing'
+    return true
+  }
+
+  get isPaused(): boolean { return this.gameState === 'paused' }
+
   /** 触发胜利 */
   triggerVictory(): void {
     if (this.gameState === 'playing') {