refactor: 提取分页魔法数字为 pagination 常量

- handler 层: device/log/webhook/user handler 使用 pagination.DefaultPageSize/MaxPageSize
- service 层: device/login_log/operation_log service 使用 pagination.DefaultPageSize
- repository 层: user repository 使用 pagination.DefaultPageSize/MaxPageSize
- 消除 8 处硬编码的 20/100 分页魔法数字

internal/api/handler/webhook_handler.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/gin-gonic/gin"
 
+	"github.com/user-management-system/internal/pagination"
 	"github.com/user-management-system/internal/service"
 )
 
@@ -66,12 +67,12 @@ 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", "20"))
+	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", strconv.Itoa(pagination.DefaultPageSize)))
 	if page < 1 {
 		page = 1
 	}
-	if pageSize < 1 || pageSize > 100 {
-		pageSize = 20
+	if pageSize < 1 || pageSize > pagination.MaxPageSize {
+		pageSize = pagination.DefaultPageSize
 	}
 	offset := (page - 1) * pageSize
 
@@ -178,9 +179,9 @@ func (h *WebhookHandler) GetWebhookDeliveries(c *gin.Context) {
 		return
 	}
 
-	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
-	if limit < 1 || limit > 100 {
-		limit = 20
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", strconv.Itoa(pagination.DefaultPageSize)))
+	if limit < 1 || limit > pagination.MaxPageSize {
+		limit = pagination.DefaultPageSize
 	}
 
 	deliveries, err := h.webhookService.GetWebhookDeliveries(c.Request.Context(), id, limit)