refactor: 使用 pagination.ClampPageSize 简化 handler 分页代码

- device/log/webhook handler: 替换 if/else 分页限制为 ClampPageSize
- 统一添加 page < 1 检查（device/log handler 缺失）

internal/api/handler/webhook_handler.go

@@ -67,13 +67,11 @@ func (h *WebhookHandler) CreateWebhook(c *gin.Context) {
 // @Router /api/v1/webhooks [get]
 func (h *WebhookHandler) ListWebhooks(c *gin.Context) {
 	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
-	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", strconv.Itoa(pagination.DefaultPageSize)))
 	if page < 1 {
 		page = 1
 	}
-	if pageSize < 1 || pageSize > pagination.MaxPageSize {
-		pageSize = pagination.DefaultPageSize
-	}
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", strconv.Itoa(pagination.DefaultPageSize)))
+	pageSize = pagination.ClampPageSize(pageSize)
 	offset := (page - 1) * pageSize
 
 	userID, _ := c.Get("user_id")