feat(frontend): add unified MCP types and API layer for v3.7.0

## Type Definitions
- Update McpServer interface with new apps field (McpApps)
- Add McpApps interface for multi-app enable state
- Add McpServersMap type for server collections
- Mark enabled field as deprecated (use apps instead)
- Maintain backward compatibility with optional fields

## API Layer Updates
- Add unified MCP management methods to mcpApi:
  * getAllServers() - retrieve all servers with apps state
  * upsertUnifiedServer() - add/update server with apps
  * deleteUnifiedServer() - remove server
  * toggleApp() - enable/disable server for specific app
  * syncAllServers() - sync all enabled servers to live configs
- Import new McpServersMap type

## Code Organization
- Keep all types in src/types.ts (removed duplicate types/mcp.ts)
- Follow existing project structure conventions

Related: v3.7.0 unified MCP management

src/lib/api/mcp.ts

@@ -3,6 +3,7 @@ import type {
   McpConfigResponse,
   McpServer,
   McpServerSpec,
+  McpServersMap,
   McpStatus,
 } from "@/types";
 import type { AppId } from "./types";
@@ -94,4 +95,47 @@ export const mcpApi = {
   async importFromGemini(): Promise<number> {
     return await invoke("import_mcp_from_gemini");
   },
+
+  // ========================================================================
+  // v3.7.0 新增：统一 MCP 管理 API
+  // ========================================================================
+
+  /**
+   * 获取所有 MCP 服务器（统一结构）
+   */
+  async getAllServers(): Promise<McpServersMap> {
+    return await invoke("get_mcp_servers");
+  },
+
+  /**
+   * 添加或更新 MCP 服务器（统一结构）
+   */
+  async upsertUnifiedServer(server: McpServer): Promise<void> {
+    return await invoke("upsert_mcp_server", { server });
+  },
+
+  /**
+   * 删除 MCP 服务器
+   */
+  async deleteUnifiedServer(id: string): Promise<boolean> {
+    return await invoke("delete_mcp_server", { id });
+  },
+
+  /**
+   * 切换 MCP 服务器在指定应用的启用状态
+   */
+  async toggleApp(
+    serverId: string,
+    app: AppId,
+    enabled: boolean,
+  ): Promise<void> {
+    return await invoke("toggle_mcp_app", { serverId, app, enabled });
+  },
+
+  /**
+   * 手动同步所有启用的 MCP 服务器到对应的应用
+   */
+  async syncAllServers(): Promise<void> {
+    return await invoke("sync_all_mcp_servers");
+  },
 };