feat(mcp): integrate MCP Server into backend service as built-in endpoint

- Add MCP Controller and register /mcp route
- MCP Server now uses OpenAPI Token for authentication
- Update frontend settings to show built-in MCP endpoint config
- Update docs to reflect integrated MCP endpoint

internal/router/router.go

@@ -35,6 +35,7 @@ type Controllers struct {
 	Interconnect *controllers.InterconnectController
 	Data         *controllers.DataController
 	Install      *controllers.InstallController
+	MCP          *controllers.MCPController
 }
 
 func Setup(c *Controllers) *gin.Engine {
@@ -79,6 +80,9 @@ func Setup(c *Controllers) *gin.Engine {
 	initAgentAPIRoutes(root, c)
 	initOpenAPIV1Routes(root, c)
 
+	// 5. [ location /mcp ] MCP Server 路由（供 AI Agent 使用）
+	initMCPRoutes(root, c)
+
 	// =========================================================================
 	// [ location / ] 全局 404 兜底与 SPA 渲染
 	// 对应 Nginx: try_files $uri $uri/ /index.html;