test(sync): cross-region simulation integration suite

P2 Task 11: 六幕串行场景套件（cn+ov 双入口进程内起真服务，真实双
MySQL/MinIO/HMAC/WS）——①端到端复制+互动+统计回传（A25 观众路径只打
ov、A27 快照替换）②隐藏传播（high 优先+WS photo.hidden+恢复发布复原）
③发送器停机积压→排空追平→对账稳态④墓碑不复活（旧 published 重放拒绝
+bootstrap 重跑仍隐藏，A26）⑤紧急停用（ov 404/WS error、cn 无感、enable
复原含新照片）⑥50 并发点赞/30 并发浏览幂等小样（终值==Σdelta、恰+15）。

services/sync devDeps 增 ws/@types/ws/ioredis（WS 场景客户端 + 限速
滑窗键清场，同 api spec 约定；版本与 api 对齐）。

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

services/sync/package.json

@@ -2,7 +2,7 @@
   "name": "@photo/sync",
   "version": "0.1.0",
   "private": true,
-  "description": "CN→OV sync process (outbox sender + ov reconciliation scheduler; P2 Task 3/4)",
+  "description": "CN→OV sync process (outbox sender + ov reconciliation scheduler + stat return; P2 Task 3/4/9)",
   "scripts": {
     "build": "tsc -p tsconfig.build.json",
     "start": "tsc -p tsconfig.build.json && node dist/main.js",
@@ -25,11 +25,14 @@
     "@types/jest": "^29.5.13",
     "@types/node": "^22.10.0",
     "@types/supertest": "^6.0.2",
+    "@types/ws": "^8.5.12",
     "dotenv": "^16.4.5",
+    "ioredis": "^6.0.0",
     "jest": "^29.7.0",
     "sharp": "^0.35.0",
     "supertest": "^7.0.0",
     "ts-jest": "^29.2.5",
-    "typescript": "^5.6.0"
+    "typescript": "^5.6.0",
+    "ws": "^8.18.0"
   }
 }