fix(router): trust all proxies to fix MCP 'invalid Host header' error

- Set TrustedProxies to nil to allow reverse proxy requests
- Add explicit routes for /mcp without trailing slash

internal/router/router.go

@@ -43,6 +43,11 @@ func Setup(c *Controllers) *gin.Engine {
 		gin.SetMode(gin.ReleaseMode)
 	}
 	router := gin.New()
+	
+	// 信任所有反向代理（Docker/Nginx 场景）
+	// 设置为 nil 表示信任所有，避免 "invalid Host header" 错误
+	router.SetTrustedProxies(nil)
+	
 	router.Use(middleware.GinLogger(), middleware.GinRecovery())
 	router.Use(middleware.TravelProxyMiddleware())