feat: 完成 Web2App 核心功能实现

- Electron 主进程：窗口管理、IPC、项目读写、打包引擎
- Vue 3 前端：4 个视图页面、3 个组件、Pinia 状态管理
- 生成应用模板：Express 后端 + Electron 窗口
- 支持资源导入、应用配置、跨平台打包

template/package.json

@@ -0,0 +1,20 @@
+{
+  "name": "generated-app",
+  "version": "1.0.0",
+  "description": "Generated by Web2App",
+  "main": "main.js",
+  "scripts": {
+    "start": "electron .",
+    "build": "electron-builder",
+    "postinstall": "electron-builder install-app-deps"
+  },
+  "dependencies": {
+    "express": "^4.18.0",
+    "cors": "^2.8.5",
+    "better-sqlite3": "^11.0.0"
+  },
+  "devDependencies": {
+    "electron": "^28.0.0",
+    "electron-builder": "^24.9.0"
+  }
+}