fix: 话题路由和会话恢复消息修正

[lishuceo]

Summary

• 解析 message.root_id，用户在已有话题内发消息时直接复用该话题，不再重复创建新话题和发送问候
• 根据 conversationId 区分"新会话已创建"和"会话已恢复"问候语，避免恢复会话时显示错误提示
• 会话过期时间从 2 小时延长到 24 小时；更新 README PM2 部署文档

Test plan

• npm run build 编译通过
• npm test 45 个测试全部通过
• 飞书实测：话题内发消息只收到一条回复，无重复卡片

🤖 Generated with Claude Code

[claude]

Claude finished @lishuceo's task in 1m 11s —— View job

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Code Review: fix/thread-routing-and-session-resume

• Check for previous review comments — none found
• Read project context (CLAUDE.md, architecture)
• Review all 3 changed files in full context
• Post review findings

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✅ Approved

Overall assessment: This is a clean, well-scoped fix that addresses two concrete UX problems — duplicate thread creation and incorrect greeting text on session resume.

Changes reviewed:

1. src/feishu/event-handler.ts — Core logic changes:

   • parseMessage now extracts message.root_id (with proper falsy-to-undefined coercion at line 443).
   • ensureThread gains a rootId parameter with correct 3-way branching: (1) reuse existing thread if rootId is present, (2) use stored thread info, (3) create new thread with appropriate greeting.
   • handleSlashCommand correctly resolves threadRootMsgId as rootId || currentSession?.threadRootMessageId, ensuring slash commands within a thread reply to the right place.
   • The isResumed check (!!session.conversationId) is correct — conversationId is only set after a successful Claude execution, so it accurately distinguishes new vs. resumed sessions.

2. src/session/manager.ts — Session expiry changed from 2h to 24h. The cleanup interval in index.ts (30 min) remains appropriate since it's independent of the TTL.

3. README.md — PM2 documentation expanded with common commands. No issues.

No bugs, security issues, or architectural concerns found. The rootId threading logic correctly handles all three scenarios (in-thread, out-of-thread with prior thread, and brand new) and the parameter is properly threaded through handleSlashCommand and executeClaudeTask.