feat(chat): scoped status and help for owner private conversations

[huangruiteng]

Owner private Chat currently answers /status with a generic ready/busy message, leaving the selected workspace, role and durable queue invisible. This change uses the existing typed bound-request owner to persist a timestamped status snapshot and adds /help. It reports only the independently verified binding's context, executor endpoint, canonical active Turn and queued-Turn count; unknown or missing evidence stays unavailable. Replays and recovery retain the original snapshot without a new Session, model call, Goal or duplicate reply. Lark owns localization; Settings and the bilingual RFC explain the entry.

本人私聊的 /status 原来只有笼统就绪/忙碌提示。现在显示实际授权工作区、角色、执行器与持久队列，/help 列出当前角色命令及现有解绑入口。状态是带时间的观测；执行结束不等于 Goal 验收或结果投递，执行器也不冒充注册 Agent。重复事件与回复读回恢复保留原快照；新机配置、账号信息及真实聊天不进入此 diff。

Depends on #5542, based on its exact public head a0c3d6817f3ac56e0e6ae6bbfcfc1ed9409fabbf. This PR contains only the status/help delta; it does not duplicate #5538 or the service change in #5543. The help command and status snapshot extend the existing conversation request owner; provider status labels remain local presentation.

Validation on final tree 57c565b729bbec99cad298186446f46e7739785f:

• 192 distinct relevant Python tests passed across focused conversation and architecture/maintainability suites (collection confirms the union); 9 typed conversation tests passed.
• Both TypeScript checks and Chat build passed; Ruff, configured strict Mypy (19 files), semantic advisory/full drift and the unchanged 275-site I/O census passed.
• Standard premerge: 5 direct checks and all 19 selected checks passed, with zero failures/warnings.
• Production native filesystem store, durable queue and provider admission/reconciliation were exercised with a synthetic provider/protocol executor: slow Turn + queued follow-up, stop, frozen replay, unreadable/unknown state, empty steward and pending reply readback recovery.

Live provider/mobile and installed-service acceptance of this delta remain unrun. Existing source services are not promoted by this PR. Registered Agent selection and broader coordination remain open. Remote CI is pending; runtime promotion requires maintainer review. 本增量未宣称真实飞书、手机或正式安装验收，也不豁免既有依赖 CI 的失败。

Additional local composition evidence: exact candidate ec6889bca2ff00f35789208fceb4e0d373941baf combines this head and #5543 on current main. All 328 relevant integration tests passed. An isolated installed wheel ran six status/help and recovery cases through its own imported native/typed/provider owners (synthetic provider/protocol executor), plus the existing macOS helper install/restart/context-preservation, frozen identity and rejection/rollback canary; all canary services were removed. Installed metadata remains 1.2.4 and is recorded separately from the source SHA. This is candidate qualification, not live-provider or mobile acceptance, nor formal upgrade.

CI checkpoint (2026-10-04): the exact head 2b83fa8e1b6530caa3bc608e9014cb12c9b3732a completed with 27 successful, 7 skipped and 6 failed checks in run 37164790228. Its 71 distinct failing test names equal the previously observed #5542/#5543 sets. This is a name-set comparison, not complete attribution to main or a waiver. The PR remains unmerged and unqualified for formal promotion.

中文 CI 更新：确切 head 当前为 27 成功、7 跳过、6 失败；71 个失败测试名称与此前 #5542/#5543 的集合相同。该比较不能替代完整归因、CI 修复和维护者合并门禁；仍未正式升级。