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/pr/SKILL.md

@@ -77,6 +77,23 @@ The ladder rules live in one place only: section 「PR 分支階梯」 of `jsc-m
     Then report the PR with the table format in `jsc-meta/references/pr-report.md`, followed by the base branch, the target branch, which of the three calibration items were updated, the feature trunk the script auto-created when step 4 printed that line, and every comment that got no reply.
 
     Done when every handled comment holds either a reply link or a recorded failure reason, and the report includes the PR table columns `{owner}/{repo}`, PR number, PR URL and PR summary, names all branch and calibration details, and names the comments that got no reply.
+10. Record how this run ended, as the very last thing this skill does:
+
+    `jsc-hooks/tools/report-status.sh skill-end jsc-git:pr {status} {exit} "{detail}"`
+
+    Resolve that path the way this file already resolves `jsc-gitea/tools/gitea.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 PR that is open stays open whether or not the run could be recorded.
+
+    | status | This skill's case |
+    | --- | --- |
+    | `ok` | A PR URL is held, the prerequisite is settled by a `pr-depend` exit 0 or by a description that names none, and every handled comment holds a reply link. Calibrating an existing PR and changing none of the three items is `ok` as well: silence is the correct outcome there |
+    | `blocked` | The ladder refused before anything was pushed: `base-branch.sh` exit 3 (origin unreachable), exit 4 (the caller base is not on origin), exit 7 (no unique legal base), exit 8 (the derived base is missing on origin) or exit 9 (the auto-create failed). No branch reached origin and no PR was opened |
+    | `degraded` | The PR is open but part of the close-out did not land: `pr-depend` exit 4 sent the run to the `WIP:` fallback, so the dependency is not on the PR, or a handled comment ended with a recorded failure instead of a reply link |
+    | `failed` | The run got partway and then git or the API refused: `pick-type.sh` exit 3 (commits exist but no subject carries a ladder type), a push that failed, `pr-create` exit 4, or a non-zero `pr-edit` that left the old title and description in place |
+    | `aborted` | **`pick-type.sh` exit 2 — step 2 produced no commit, so there is nothing to open a PR for.** That is a run which correctly stopped, not a run that failed and not a run that succeeded; recording it as anything else is what made a round with no change look identical to a round that shipped eight PRs. The user declining the confirmation before `pr-create`, `pr-edit` or `pr-depend` is `aborted` too |
+
+    `{exit}` is the exit code of whatever decided the status, `0` for `ok` — so the no-change round above carries `aborted` with `2`. `{detail}` is one short line well under 200 characters: counts and exit codes plus which of the three calibration items moved, never the PR title, the PR number, branch names, or personal data.
+
+    Done when the command has run, or the script was absent and this step was skipped.
 
 ## Rules