refactor(admin): decouple system cleanup with event bus and enforce single owner principle

backend/plugins/domain/admin/plugin.go

@@ -21,6 +21,12 @@ import (
 // SystemConfig aliases model.SystemConfig for external compatibility.
 type SystemConfig = model.SystemConfig
 
+// TaskExecution aliases model.TaskExecution for external compatibility.
+type TaskExecution = model.TaskExecution
+
+// Schedule aliases model.Schedule for external compatibility.
+type Schedule = model.Schedule
+
 //go:embed migrations/*/*.sql
 var adminMigrations embed.FS
 
@@ -132,12 +138,17 @@ func (p *Plugin) Apply(ctx *core.Context) error {
 	ctx.Router().RegisterWhitelist("/robots.txt")
 
 	// 2. Register Background Tasks
+	const defaultCleanupRetry = 3
 	ctx.Task().Register(service.LogDBSwitchTask, &service.LogDBSwitchHandler{}, extpoints.WithTaskMeta(service.LogDBSwitchMeta))
+	ctx.Task().Register(service.SystemCleanupTask, &service.SystemCleanupHandler{}, extpoints.WithTaskMeta(service.SystemCleanupMeta), extpoints.WithTaskRetry(defaultCleanupRetry))
+
+	// 2.1 Register Cron Schedule
+	ctx.Schedule().RegisterCron("0 3 * * *", service.SystemCleanupTask, nil)
 
 	// 3. Register Settings Schemas
 	ctx.Settings().Register(extpoints.SettingSchema{
 		Key:         "admin.system_cleanup_cron",
-		Default:     "0 4 * * *",
+		Default:     "0 3 * * *",
 		Description: "Cron expression for nightly system logs and expired tokens cleanup",
 		Type:        "string",
 		Category:    "maintenance",

backend/plugins/domain/admin/plugin_test.go

@@ -36,11 +36,13 @@ func TestAdminPluginUnit(t *testing.T) {
 	// Verify tasks
 	_, ok := ctx.Tasks().Get("logs:db_switch")
 	require.True(t, ok)
+	_, ok = ctx.Tasks().Get("system:cleanup")
+	require.True(t, ok)
 
 	// Verify settings
 	setting, ok := ctx.Settings().Get("admin.system_cleanup_cron")
 	require.True(t, ok)
-	assert.Equal(t, "0 4 * * *", setting.Default)
+	assert.Equal(t, "0 3 * * *", setting.Default)
 
 	provider, err := core.Inject[contracts.PublicConfigProvider](ctx)
 	require.NoError(t, err)

backend/plugins/domain/admin/service/cleanup.go

@@ -0,0 +1,70 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package service
+
+import (
+	"Wavelet/core/contracts"
+	"Wavelet/pkg/logger"
+	"Wavelet/plugins/domain/admin/model"
+	"context"
+	"errors"
+	"fmt"
+	"time"
+)
+
+const (
+	// SystemCleanupTask 系统定期垃圾清理任务标识
+	SystemCleanupTask = "system:cleanup"
+	// TaskTypeSystemCleanup 系统定期垃圾清理管理类型
+	TaskTypeSystemCleanup = "system_cleanup"
+	taskQueueDefault      = "default"
+)
+
+// SystemCleanupMeta describes the system-wide cleanup task metadata.
+var SystemCleanupMeta = contracts.TaskMetaDTO{
+	Type:         TaskTypeSystemCleanup,
+	AsynqTask:    SystemCleanupTask,
+	Name:         "系统垃圾清理",
+	DisplayName:  "系统垃圾清理",
+	Description:  "定期清理过期任务执行记录，并通过领域事件广播触发各业务域自治清理（临时文件、历史推送等）",
+	Category:     "maintenance",
+	SupportsTime: false,
+	MaxRetry:     3,
+	Queue:        taskQueueDefault,
+	Retryable:    true,
+}
+
+// SystemCleanupHandler handles the system-wide garbage cleanup task.
+type SystemCleanupHandler struct{}
+
+// Execute executes system cleanup: clears old task executions and emits EventTopicSystemCleanup.
+func (h *SystemCleanupHandler) Execute(ctx context.Context, _ []byte) (*contracts.TaskResultDTO, error) {
+	db := GetDB(ctx)
+	if db == nil {
+		return nil, errors.New("database service not available")
+	}
+
+	// 1. 清理自身域（admin 域）的过期任务执行记录（7 天前）
+	var deletedExecutions int64
+	sevenDaysAgo := time.Now().Add(-7 * 24 * time.Hour)
+	res := db.Where("created_at < ?", sevenDaysAgo).Delete(&model.TaskExecution{})
+	if err := res.Error; err != nil {
+		logger.WarnF(ctx, "清理过期任务执行日志失败: %v", err)
+	} else {
+		deletedExecutions = res.RowsAffected
+		logger.InfoF(ctx, "已清理 7 天前任务执行日志，共 %d 条", deletedExecutions)
+	}
+
+	// 2. 广播 EventTopicSystemCleanup 领域事件，由各业务域插件（upload, msg_gateway, user 等）自治执行各自的清理逻辑
+	nowStr := time.Now().Format(time.RFC3339)
+	if err := EmitEvent(ctx, contracts.EventTopicSystemCleanup, contracts.SystemCleanupEvent{
+		TriggeredAt: nowStr,
+	}); err != nil {
+		logger.WarnF(ctx, "广播系统清理领域事件失败: %v", err)
+	}
+
+	msg := fmt.Sprintf("系统垃圾清理完成，已清理过期任务执行日志 %d 条，并已广播领域清理事件", deletedExecutions)
+	logger.InfoF(ctx, "%s", msg)
+	return &contracts.TaskResultDTO{Message: msg}, nil
+}

backend/plugins/domain/admin/service/cleanup_test.go

@@ -0,0 +1,78 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package service_test
+
+import (
+	"Wavelet/core/contracts"
+	"Wavelet/plugins/domain/admin/model"
+	"Wavelet/plugins/domain/admin/service"
+	"context"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/glebarez/sqlite"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm"
+)
+
+func TestSystemCleanupHandler_Execute(t *testing.T) {
+	sqliteDB, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
+	require.NoError(t, err)
+
+	require.NoError(t, sqliteDB.AutoMigrate(&model.TaskExecution{}))
+
+	service.SetDBService(&testDBService{db: sqliteDB})
+	defer service.ResetServices()
+
+	now := time.Now()
+	oldTime := now.Add(-10 * 24 * time.Hour)
+	recentTime := now.Add(-1 * time.Hour)
+
+	// Seed old execution (should be cleaned)
+	oldExec := model.TaskExecution{
+		ID:        1,
+		TaskID:    "task-old",
+		TaskType:  "sample_task",
+		Status:    "success",
+		CreatedAt: oldTime,
+	}
+	require.NoError(t, sqliteDB.Create(&oldExec).Error)
+
+	// Seed recent execution (should remain)
+	recentExec := model.TaskExecution{
+		ID:        2,
+		TaskID:    "task-recent",
+		TaskType:  "sample_task",
+		Status:    "success",
+		CreatedAt: recentTime,
+	}
+	require.NoError(t, sqliteDB.Create(&recentExec).Error)
+
+	var eventFired atomic.Bool
+	service.SetEventEmitter(func(ctx context.Context, topic string, payload any) error {
+		if topic == contracts.EventTopicSystemCleanup {
+			eventFired.Store(true)
+		}
+		return nil
+	})
+
+	handler := &service.SystemCleanupHandler{}
+	res, err := handler.Execute(context.Background(), nil)
+	require.NoError(t, err)
+	require.NotNil(t, res)
+	assert.Contains(t, res.Message, "系统垃圾清理完成")
+
+	// Verify old execution is deleted and recent remains
+	var count int64
+	sqliteDB.Model(&model.TaskExecution{}).Count(&count)
+	assert.Equal(t, int64(1), count)
+
+	var remaining model.TaskExecution
+	sqliteDB.First(&remaining)
+	assert.Equal(t, uint64(2), remaining.ID)
+
+	assert.True(t, eventFired.Load(), "EventTopicSystemCleanup must be emitted")
+}