phase 5 prep: backfill-users.ts + deployment runbook in .memory

- scripts/backfill-users.ts: 扫 PG users 表,对每人幂等调 orchestrator POST /users
- orchestrator/package.json: 加 postgres 依赖
- .memory/project.md: Phase 3/4 完成状态,Phase 5 上线 checklist

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.memory/worklog.json

@@ -160,6 +160,13 @@
       "message": "orchestrator MVP: 13 工具跑通 + systemd + 部署脚本",
       "hash": "ce8e22f",
       "files_changed": 1
+    },
+    {
+      "ts": "2026-04-19T21:12:27+08:00",
+      "type": "commit",
+      "message": "auto-save 2026-04-19 21:12 (~1)",
+      "hash": "e7155b7",
+      "files_changed": 1
     }
   ]
 }