修复：为 user-svc 添加健康检查和启动顺序控制

backend/gateway/cmd/main.go

@@ -5,11 +5,12 @@ import (
 	"log"
 	"net/http"
 
-	"backend/gateway/internal/config"
-	"backend/gateway/internal/router"
-	"backend/gateway/internal/service"
-	"backend/gateway/internal/ws"
-	"backend/shared/pkg/logger"
+	"gateway/internal/config"
+	"gateway/internal/router"
+	"gateway/internal/service"
+	"gateway/internal/ws"
+
+	"shared/pkg/logger"
 )
 
 func main() {