feat(pwa): 集成 PWA 支持并配置离线缓存策略

- 添加 vite-plugin-pwa 插件依赖
- 配置应用清单(manifest)支持全屏模式
- 设置工作箱(workbox)缓存静态资源
- 实现图片和音频资源的运行时缓存
- 调整缓存大小限制至 5MB 以适应游戏资源
- 更新构建时间戳

package.json

@@ -9,7 +9,7 @@
   },
   "private": true,
   "version": "1.2.5",
-  "buildDate": "2025/12/15 20:03:44",
+  "buildDate": "2025/12/15 21:21:23",
   "main": "dist-electron/main.js",
   "type": "module",
   "scripts": {
@@ -55,6 +55,7 @@
     "vite": "npm:rolldown-vite@7.2.5",
     "vite-plugin-electron": "^0.29.0",
     "vite-plugin-electron-renderer": "^0.14.6",
+    "vite-plugin-pwa": "^1.2.0",
     "vue-tsc": "^3.1.4"
   },
   "pnpm": {