[Bug]: Feishu bot messages never delivered; channel stuck at 'Connected' after Feishu-side revocation, blocking re-bind

Summary

An agent's Feishu (Lark) bot silently stops receiving messages, and after the bot authorization is revoked on the Feishu side, Multica never detects it: the channel card still shows Connected (已连接), the stale connection record blocks re-binding (connected agents don't show the QR-code entry), and all messages sent to the bot vanish with zero delivery — not even the account-binding link that first-time users are supposed to receive.

Environment

• Multica Cloud (https://api.multica.ai)
• Workspace ID: f8b0b0b1-b288-4d5e-95f6-a221c26e8324
• Agent: hermes-MBP (built-in Mika system agent), ID 9237c6fa-266b-40ea-944f-73512dad4851
• Agent runtime: Hermes Agent v0.21.3, local runtime e3aefc23-a842-40c9-b138-1446f7b46213 — online throughout (verified via multica runtime list)
• CLI: multica v0.4.44, macOS (daemon healthy, uptime >9h)
• Feishu: mainland-China version

Timeline (all times +08)

1. 2026-09-16 19:31:40 — Bot hermes-MBP installed/bound via the agent's Integrations page (QR scan + authorization confirmed; Multica showed the connection).
2. After binding, the workspace owner sent private-chat messages to the bot in Feishu — zero response of any kind (no reply, no error, no account-binding link).
3. Troubleshooting verified every documented cause ("Bot doesn't run"): agent not archived, runtime online, concurrency cap not reached (2/3), private chat (not group).
4. Evidence from multica agent tasks <agent-id> --output json: since the bot was installed, not a single run was enqueued from the Feishu channel — every run in the window has attribution.source = "direct_human" from the desktop chat. The messages never reached Multica's backend (or were dropped before dispatch).
5. The bot authorization was later revoked on the Feishu side. The bot detail entry in Multica now shows 已撤销 (Revoked), but:
   • the 消息渠道 (Channels) card still shows 飞书 · 已连接 (Connected) in green — state desync;
   • because Multica still considers the agent connected, the QR-code re-binding entry is not shown (documented behavior: "已经连接的智能体不会再次显示扫码入口"), leaving no way to re-establish the connection.

Expected behavior

1. Messages sent to a bound bot in a private chat are delivered and answered (or at minimum the account-binding link is returned).
2. When the Feishu-side authorization/install is revoked, Multica detects it (uninstall event / callback failure / health check) and updates the channel status accordingly.
3. A broken/revoked connection can be cleaned up and re-bound — the scan entry should reappear once the connection is effectively dead.

Actual behavior

• Zero message delivery from Feishu since installation, with the connection shown as healthy.
• After revocation: stale "Connected" status on the channel card, "已撤销" on the bot detail entry, and no path to re-bind.

Steps to reproduce

1. Bind an agent to Feishu via Integrations → 绑定到飞书.
2. Revoke/uninstall the bot on the Feishu side (or let authorization lapse).
3. Send a private-chat message to the bot → no response.
4. Open Settings → 消息渠道 → Feishu still shows 已连接; agent Integrations page offers no scan/re-bind entry.

Additional notes

• Screenshots of (a) the connected-bot record with install timestamp, (b) the revoked (已撤销) bot entry, and (c) the channel card stuck at 已连接 are available and can be attached on request.
• Possibly related: #2454 (per-agent Feishu bot registration), #4210 (cross-workspace bot scope).