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/service/device.go

@@ -223,7 +223,7 @@ func (s *DeviceService) GetUserDevices(ctx context.Context, userID int64, page,
 		page = 1
 	}
 	if pageSize <= 0 {
-		pageSize = 20
+		pageSize = pagination.DefaultPageSize
 	}
 
 	offset := (page - 1) * pageSize
@@ -275,7 +275,7 @@ func (s *DeviceService) GetActiveDevices(ctx context.Context, page, pageSize int
 		page = 1
 	}
 	if pageSize <= 0 {
-		pageSize = 20
+		pageSize = pagination.DefaultPageSize
 	}
 
 	offset := (page - 1) * pageSize

internal/service/login_log.go

@@ -228,7 +228,7 @@ func (s *LoginLogService) GetMyLoginLogs(ctx context.Context, userID int64, page
 		page = 1
 	}
 	if pageSize <= 0 {
-		pageSize = 20
+		pageSize = pagination.DefaultPageSize
 	}
 	offset := (page - 1) * pageSize
 	return s.loginLogRepo.ListByUserID(ctx, userID, offset, pageSize)

internal/service/operation_log.go

@@ -143,7 +143,7 @@ func (s *OperationLogService) GetMyOperationLogs(ctx context.Context, userID int
 		page = 1
 	}
 	if pageSize <= 0 {
-		pageSize = 20
+		pageSize = pagination.DefaultPageSize
 	}
 	offset := (page - 1) * pageSize
 	return s.operationLogRepo.ListByUserID(ctx, userID, offset, pageSize)