feat: 配置列表分页与钉钉机器人分钟级排队限流

统一 sources/templates/channels/rules 列表为分页响应，避免配置增多时全量返回；按钉钉 access_token 限制每分钟发送并在超限时等待下一分钟，降低触发官方封禁风险。

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

internal/handler/channel.go

@@ -47,12 +47,19 @@ func (h *ChannelHandler) Create(c *gin.Context) {
 }
 
 func (h *ChannelHandler) List(c *gin.Context) {
-	channels, err := h.store.ListChannels(c.Request.Context())
+	var page store.PageFilter
+	if err := c.ShouldBindQuery(&page); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	page.Normalize()
+
+	channels, total, err := h.store.ListChannels(c.Request.Context(), page)
 	if err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
-	c.JSON(http.StatusOK, channels)
+	c.JSON(http.StatusOK, gin.H{"data": channels, "total": total, "page": page.Page})
 }
 
 func (h *ChannelHandler) Get(c *gin.Context) {