Refactor Qiniu upload integration and remove legacy handlers

- Replaced common upload handler and service with Qiniu-specific implementations in main.go and route registration.
- Deleted outdated upload_handler.go and qiniu_service.go files to streamline the codebase.
- Updated route definitions to utilize the new Qiniu upload handler for improved file upload management.

internal/routes/common_routes.go

@@ -3,10 +3,10 @@ package routes
 import (
 	"github.com/gin-gonic/gin"
 
-	commonhandler "wx_service/internal/common/handler"
+	qiniuhandler "wx_service/internal/common/qiniu/handler"
 )
 
-func registerCommonRoutes(protected *gin.RouterGroup, uploadHandler *commonhandler.UploadHandler) {
+func registerCommonRoutes(protected *gin.RouterGroup, uploadHandler *qiniuhandler.UploadHandler) {
 	// 公共接口（所有小程序共用）
 	common := protected.Group("/common")
 	{