refactor(tauri): 移除持久化存储和HTTP插件优化应用架构

- 移除了 tauri-plugin-persisted-scope 和 tauri-plugin-http 插件依赖
- 从桌面功能权限中移除了文件系统和HTTP访问权限
- 删除了相关的存储键常量定义
- 修改悬浮列表窗口创建逻辑，移除页面类型参数和动态计算功能
- 主窗口配置调整为非透明背景并设置白色背景色
- 移除了前端悬浮列表中互动课堂和智评会议相关功能组件
- 更新Cargo.lock移除相关依赖包确保构建一致性

src-tauri/capabilities/desktop.json

@@ -3,25 +3,5 @@
   "identifier": "desktop-capability",
   "platforms": ["macOS", "windows", "linux"],
   "windows": ["main", "meeting", "meeting2", "popup", "float-list"],
-  "permissions": [
-    "dialog:default",
-    "updater:default",
-    "process:default",
-    "process:allow-exit",
-    "fs:default",
-    "fs:allow-write-file",
-    "fs:allow-download-write",
-    "websocket:default",
-    {
-      "identifier": "http:default",
-      "allow": [
-        {
-          "url": "http://*:*"
-        },
-        {
-          "url": "https://*:*"
-        }
-      ]
-    }
-  ]
+  "permissions": ["dialog:default", "updater:default", "process:default", "process:allow-exit", "websocket:default"]
 }