feat: rename qiniu to oss, add admin upload proxy with thumbnail, add dev-login

- Rename all QINIU_* config/code/docs to OSS_* to match actual Alibaba Cloud OSS
- Refactor upload module from internal/common/qiniu to internal/common/upload
- Add backend proxy upload endpoint (POST /api/admin/marketing/upload) to avoid CORS
- Auto-generate compressed thumbnail (800px, JPEG 80%) on admin image upload
- Add dev-login endpoint (POST /api/v1/auth/dev-login) for H5 debugging
- Add imageutil package for server-side image resizing

Made-with: Cursor

internal/routes/common_routes.go

@@ -3,19 +3,16 @@ package routes
 import (
 	"github.com/gin-gonic/gin"
 
-	qiniuhandler "wx_service/internal/common/qiniu/handler"
+	uploadhandler "wx_service/internal/common/upload/handler"
 )
 
-func registerCommonPublicRoutes(api *gin.RouterGroup, uploadHandler *qiniuhandler.UploadHandler) {
-	// 七牛上传回调：由七牛服务端调用，不能挂登录鉴权。
-	api.POST("/common/upload/qiniu/callback", uploadHandler.QiniuCallback)
+func registerCommonPublicRoutes(api *gin.RouterGroup, uploadHandler *uploadhandler.UploadHandler) {
+	api.POST("/common/upload/oss/callback", uploadHandler.UploadCallback)
 }
 
-func registerCommonRoutes(protected *gin.RouterGroup, uploadHandler *qiniuhandler.UploadHandler) {
-	// 公共接口（所有小程序共用）
+func registerCommonRoutes(protected *gin.RouterGroup, uploadHandler *uploadhandler.UploadHandler) {
 	common := protected.Group("/common")
 	{
-		// 七牛直传凭证：前端先拿 token，再直传文件到七牛 upload_url
-		common.POST("/upload/qiniu/token", uploadHandler.QiniuToken)
+		common.POST("/upload/oss/token", uploadHandler.GetUploadToken)
 	}
 }