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/worklog/SKILL.md

@@ -115,3 +115,20 @@ The `{HASH}` in every page name above is computed with `jsc-gitea/tools/hash-id`
    | 2 | The claim path is not the one `merge` produced, or it points outside this `{HASH}`'s pending directory. Rerun from step 4 with the `CLAIM` value that `merge` printed; never pass a hand-written path |
 
    Done when one of the two ran and its exit code was reported.
+8. Record how this run ended, as the very last thing this skill does:
+
+   `jsc-hooks/tools/report-status.sh skill-end jsc-log:worklog {status} {exit} "{detail}"`
+
+   Resolve that path the way row 5 already resolves `jsc-hooks/hooks/session-timer.sh` — the sibling plugin directory, no separate lookup rule for this one call. **A missing script is not a failure here: skip this step in silence and let the run end as it stands.** The script swallows its own write errors and exits 0 even then, so nothing branches on its code either. A run whose result could not be recorded still had that result, and a work log that fails because the recorder is absent is worse than no recording.
+
+   | status | This skill's case |
+   | --- | --- |
+   | `ok` | Steps 5 and 6 both wrote and step 7 cleared the pending area. `orphans` exit 4 stays `ok`: an orphan directory belongs to some other repository and changes nothing about this entry — carry its line count in `{detail}` so the count is on record even though the run passed |
+   | `blocked` | Nothing could be written and nothing was: `hash-id` exit 1 (no SHA-1 helper on this machine), `worklog-target.sh friday` exit 4 (no date arithmetic), `wiki-repo LOG` exit 3 (no LOG wiki repo configured), or `link-check.sh` exit 3 (`GITEA_HOST` unset) or exit 7 (token rejected). The gate stopped the run before a page was touched |
+   | `degraded` | The entry is on `LOG_{HASH}` but the close-out is short: `wiki-contents.sh upsert` returned non-zero so `LOG_CONTENTS` still carries the old row, or `worklog-pending.sh commit` exited 1 so the pending files survive a successful write and the next run merges them again |
+   | `failed` | Nothing reached the wiki after the run started working: `link-check.sh` exit 1 stopped the write on a DEAD link, the `PAGE` read came back 7 or 8, or `worklog-pending.sh merge` exited 1 |
+   | `aborted` | The user stopped the run, or the trigger turned out not to hold — no task ended here, so there is no entry to write and none was attempted |
+
+   `{exit}` is the exit code of whatever decided the status, `0` for `ok`. `{detail}` is one short line well under 200 characters: counts and exit codes only, never entry text, page names, branch names, or personal data.
+
+   Done when the command has run, or the script was absent and this step was skipped.