feat(清理任务): 引入Ent存储并补充日志与测试

新增 usage_cleanup_task Ent schema 与仓储实现，支持清理任务排序分页
补充清理任务全链路日志、仪表盘重算触发及 UI 过滤调整
完善 repository/service 单测并引入 sqlite 测试依赖

backend/ent/tx.go

@@ -32,6 +32,8 @@ type Tx struct {
 	RedeemCode *RedeemCodeClient
 	// Setting is the client for interacting with the Setting builders.
 	Setting *SettingClient
+	// UsageCleanupTask is the client for interacting with the UsageCleanupTask builders.
+	UsageCleanupTask *UsageCleanupTaskClient
 	// UsageLog is the client for interacting with the UsageLog builders.
 	UsageLog *UsageLogClient
 	// User is the client for interacting with the User builders.
@@ -184,6 +186,7 @@ func (tx *Tx) init() {
 	tx.Proxy = NewProxyClient(tx.config)
 	tx.RedeemCode = NewRedeemCodeClient(tx.config)
 	tx.Setting = NewSettingClient(tx.config)
+	tx.UsageCleanupTask = NewUsageCleanupTaskClient(tx.config)
 	tx.UsageLog = NewUsageLogClient(tx.config)
 	tx.User = NewUserClient(tx.config)
 	tx.UserAllowedGroup = NewUserAllowedGroupClient(tx.config)