feat(distribution): 分站品牌装修可配置首页入口并上传图片

分站可单独配置回收、合作反馈和客服二维码，未配置时继承主站；Logo、图标和轮播支持直接上传。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/modules/file/handler.go

@@ -101,7 +101,8 @@ func (h *Handler) writeObject(c *gin.Context, publicOnly bool) {
 		!strings.HasPrefix(key, "mohong/") &&
 		!strings.HasPrefix(key, "crash/") &&
 		!strings.HasPrefix(key, "aw-recycle/") &&
-		!strings.HasPrefix(key, "cooperation-feedback/") {
+		!strings.HasPrefix(key, "cooperation-feedback/") &&
+		!strings.HasPrefix(key, "support-qrcode/") {
 		response.Error(c, http.StatusNotFound, "not_found", "文件不存在或暂不可访问")
 		return
 	}