feat(ov): windowed dedup visit counting with retention cleanup

Task 8 (P2): POST /public/albums/{token}/visits with visit_sessions
window dedup (VISIT_WINDOW_MINUTES), requestId idempotent replay
(echoes stored outcome; expired beyond VISIT_REQUEST_TTL_MINUTES
rejected), album_stats viewCount/statVersion authority + outbox_stat_events
views snapshots, WS stats.updated broadcast, visitorId+IP fixed-window
rate limit (VISIT_WINDOW_REQUESTS), and ov CleanupModule scheduler
(setInterval, CLEANUP_INTERVAL_MINUTES) deleting like_batches /
visit_requests / visit_sessions past their windows — totals never
touched. Contract prose aligned to replay semantics; constants
VISIT_WINDOW_REQUESTS / CLEANUP_INTERVAL_MINUTES added.

Co-Authored-By: Claude Code <noreply@anthropic.com>

services/api/src/app-ov.module.ts

@@ -7,8 +7,9 @@
 // （public-ov：读 photos_ov 副本的同形契约端点 + hot 排序）；Task 7 起加入
 // interactions（点赞批次幂等 + Redis ov 限速）与 realtime（WS 网关：契约帧
 // 分发见 main-ov 的 ContractWsAdapter），EventEmitter2 全局总线承接「事务提交
-// → 实时广播」（ov-events.ts，单进程——多实例 P5）。cn 模块保持原样，两入口
-// 互不影响。
+// → 实时广播」（ov-events.ts，单进程——多实例 P5）；Task 8 起 interactions
+// 增浏览上报（visits：窗口去重 + requestId 幂等）并加入 cleanup（互动流水
+// 超窗口行回收调度）。cn 模块保持原样，两入口互不影响。
 import {
   type MiddlewareConsumer,
   Module,
@@ -19,6 +20,7 @@ import { APP_FILTER, APP_PIPE } from '@nestjs/core';
 import { EventEmitterModule } from '@nestjs/event-emitter';
 import { LoggerModule } from 'nestjs-pino';
 import { AllExceptionsFilter } from './all-exceptions.filter';
+import { CleanupModule } from './cleanup/cleanup.module';
 import { EmergencyModule } from './emergency/emergency.module';
 import { HealthController } from './health.controller';
 import { InteractionsModule } from './interactions/interactions.module';
@@ -44,6 +46,9 @@ import { SyncInboxModule } from './sync-inbox/sync-inbox.module';
     InteractionsModule,
     // ov 实时广播（P2 Task 7）：WS /v1/realtime（适配器见 main-ov）。
     RealtimeModule,
+    // ov 互动流水清理调度（P2 Task 8）：like_batches/visit_requests/
+    // visit_sessions 超窗口行回收（累计总数永不清理）。
+    CleanupModule,
   ],
   controllers: [HealthController],
   providers: [