feat: 添加通知处理程序，实现通知的获取、标记已读、删除、创建和广播功能。

internal/handler/notification_handler.go

@@ -73,23 +73,17 @@ func (h *NotificationHandler) GetNotifications(c *gin.Context) {
 		return
 	}
 
-	// Calculate total pages
-	totalPages := 0
-	if result.Limit > 0 {
-		totalPages = int((result.Total + int64(result.Limit) - 1) / int64(result.Limit))
-	}
-
 	// Calculate current page (1-indexed)
 	currentPage := 1
 	if result.Limit > 0 {
 		currentPage = (result.Offset / result.Limit) + 1
 	}
 
-	api.SuccessWithMeta(c, result.Notifications, &api.Meta{
-		Page:       currentPage,
-		PageSize:   result.Limit,
-		TotalCount: result.Total,
-		TotalPages: totalPages,
+	api.Success(c, gin.H{
+		"notifications": result.Notifications,
+		"total":         result.Total,
+		"page":          currentPage,
+		"limit":         result.Limit,
 	})
 }