feat(log): decouple log storage from ClickHouse with switchable logstore

- New internal/repository/logstore abstraction: exported domain interfaces
  (AccessLogStore/ObservabilityStore/UserAccessLogStore/StatusStore),
  config-driven provider (Active/Build/Migrating/SetConfigReader), GORM
  implementation for PostgreSQL/SQLite (incl. hourly rollups computed in
  real time, migration listers, PG partition maintenance), and a ClickHouse
  wrapper preserving the native batch path; repository facade delegates to
  logstore; import-lint test enforces apps never import analyticsrepo.
- ClickHouse is now optional: the log DB is either the main DB (postgres
  when database.enabled, else sqlite) or clickhouse; boot validation +
  first-run seed; log_database / log_db_migration are protected keys.
- New user task 切换日志数据库 (of_log_db_switch): freeze log writes,
  drain batch writers, copy all 6 raw log tables by id (preserving IDs)
  with target-partition pre-creation for PG, flip log_database on success,
  clear the freeze flag on failure.
- Per-store retention (log_retention_days_*) with expiry cleanup folded
  into the daily system_cleanup task; legacy database_auto_cleanup_* and
  of_database_auto_cleanup decommissioned.
- goose migrations: 6 log tables in PG (2 monthly-partitioned) + SQLite,
  retention config seeds, schedule cleanup; GET
  /api/v1/admin/status/log-database endpoint; frontend retention settings,
  switch-task UI and status badge; changelog and docs updated.

docs(plan): log database decoupling implementation plan

docs(design): log database decoupling design (ClickHouse optional)

frontend/lib/services/admin/index.ts

@@ -29,6 +29,7 @@ export type {
   UpdateUserStatusRequest,
   UpdateUserRequest,
   SystemStatus,
+  LogDatabaseStatus,
   AppUpdateStatus,
   Schedule,
   CreateScheduleRequest,

frontend/lib/services/admin/status.service.ts

@@ -1,5 +1,5 @@
 import { BaseService } from '@/lib/services/core';
-import type { AppUpdateStatus, SystemStatus } from './types';
+import type { AppUpdateStatus, LogDatabaseStatus, SystemStatus } from './types';
 
 export class AdminStatusService extends BaseService {
   protected static readonly basePath = '/api/v1/admin';
@@ -8,6 +8,10 @@ export class AdminStatusService extends BaseService {
     return this.get<SystemStatus>('/status');
   }
 
+  static async getLogDatabaseStatus(): Promise<LogDatabaseStatus> {
+    return this.get<LogDatabaseStatus>('/status/log-database');
+  }
+
   static async getUpdateStatus(): Promise<AppUpdateStatus> {
     return this.get<AppUpdateStatus>('/update');
   }

frontend/lib/services/admin/types.ts

@@ -405,6 +405,22 @@ export interface ToggleAuthSourceRequest {
   is_active: boolean;
 }
 
+/**
+ * 日志数据库状态
+ */
+export interface LogDatabaseStatus {
+  /** 当前日志主库：postgres | sqlite | clickhouse */
+  active_database: string;
+  /** 迁移状态：idle | migrating */
+  migration: string;
+  /** 各日志库保留天数 */
+  retention_days: Record<string, number>;
+  /** 当前主库的合法迁移目标 */
+  available_targets: string[];
+  /** ClickHouse 运行指标（仅主库为 ClickHouse 时） */
+  clickhouse?: unknown;
+}
+
 /**
  * 系统状态信息
  */