feat(file): unify file handling with a new FileSource abstraction for URL and base64 data

controller/redemption.go

@@ -103,9 +103,10 @@ func AddRedemption(c *gin.Context) {
 		}
 		err = cleanRedemption.Insert()
 		if err != nil {
+			common.SysError("failed to insert redemption: " + err.Error())
 			c.JSON(http.StatusOK, gin.H{
 				"success": false,
-				"message": err.Error(),
+				"message": "创建兑换码失败，请稍后重试",
 				"data":    keys,
 			})
 			return