feat(狀態回報): 收尾寫一筆 skill-end 事件

現行紀錄只記「被叫用」，沒有成敗也沒有結束碼。跑完整輪的技能與開場就
中止的技能，在紀錄裡長得一模一樣。

start 由技能用量 hook 順手發，不必改技能文件。end 只能由技能自己在收尾
步驟寫——hook 接在技能工具呼叫上，而實際工作發生在之後的模型輪次，它在
原理上看不到成敗。有 start 沒有配對的 end，就是那一輪中止了。

status 五選一，每支技能各自寫明什麼情況選哪一個。找不到回報腳本就安靜
跳過，回報失敗一律不改變技能自己的結論。

skills/skill-check/SKILL.md

@@ -130,3 +130,24 @@ Single source of guidelines: [`../../references/guidelines.md`](../../references
    - **On a failed write.** Retry once. Still failing, hand the user the page name and the full section that was not written, so the round's result is not lost. **Never close the run reporting a page as written when it was not**, and never close it silently with the content only in the transcript.
 
    Completion condition: every changed domain repo has one new section on its `SKILLSET_{HASH}` and one row in `SKILLSET_CONTENTS` written by a `wiki-contents.sh upsert` that exited 0, or — where nothing changed — the `plugins/meta` page carries the 「本輪無發現」 section and its row on the same terms; every content-page write is confirmed by a successful read-back or reported as not written with its full content handed back.
+9. Report this round's outcome to the local event stream — the last step of every run, the ones that stop early included. Run:
+
+   `jsc-hooks/tools/report-status.sh skill-end jsc-meta:skill-check {status} {exit code} [detail]`
+
+   Resolve `jsc-hooks` from the `domain<TAB>path` row step 1 printed for the `hooks` domain, the same way this skill resolves every other cross-plugin script. **When that script is not on this machine, skip this step in silence and close the round as normal.** A reporting path that is absent must never fail the run it reports on, and this call's own exit code never changes what this skill reports.
+
+   Pick `{status}` from what the round actually did:
+
+   | status | Use it when |
+   | --- | --- |
+   | `ok` | every domain ended with a complete checklist, every accepted fix passed its re-check, every affected repo has a PR URL, and every wiki write exited 0 |
+   | `blocked` | a gate or a missing prerequisite stopped the round before anything was audited — `sync-domains.sh` never reached exit 0, or the call itself was refused |
+   | `failed` | the round broke mid-way — a re-check in step 6 kept failing, or a wiki write failed again after its one retry |
+   | `degraded` | the round finished with a part missing — a domain carries 「本輪未取得已決議清單，優化建議暫不提出」, or a content page was written while its `SKILLSET_CONTENTS` row was not |
+   | `aborted` | the user stopped the round, or a prerequisite turned out not to hold and this skill stopped on its own |
+
+   `{exit code}` is this round's own result as a number: `0` for `ok`, non-zero otherwise. `detail` is optional, one line, at most 200 characters.
+
+   The matching `skill-start` comes free from the hook, which fires when the skill loads. The audit itself happens in the model turns after that, so no hook can see how the round ended — a `start` with no `end` reads as an abort, which is why writing the `end` is this skill's own job.
+
+   Completion condition: one `skill-end` line for this round is appended to `$JSC_HOME/usage/events.jsonl`, or the script was absent and the final report says so.