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/html-style/SKILL.md

@@ -15,6 +15,21 @@ One kind of page, one layout, one style. `jsc-gitea:html-export` reads what this
 4. **Pick the scope.** Ask per `jsc-ask:ask` rules: `--project` writes `./.jsc/html-styles`, which only applies inside this working directory and is committed with the repository; `--global` writes `$JSC_HOME/html-styles.conf`, which follows the user across every project on this machine. State that the project file wins whenever both hold the same key. Completion condition: the user has picked one scope.
 5. Write it: `tools/html-style.sh set {key} {layout} {style} [--project|--global]`. Route every exit code: 0 → the file it printed now holds the pair; 1 → the settings file's directory could not be created, so report the path and stop, since nothing was written; 2 → a usage error, such as a missing name or a scope flag that is neither `--project` nor `--global`, so fix the arguments and call again; 4 → the layout or style name has no template file, so go back to step 2 or step 3 rather than editing the settings file by hand. Completion condition: the script exits 0 and prints the file it wrote.
 6. Read it back with `tools/html-style.sh get {key}` and report the resolved layout, style and source. Completion condition: the source column shows `project` or `global`, matching the scope chosen in step 4.
+7. **Record how the run ended.** This is the last thing this skill does, and it runs on every path out of the skill, the ones that stop at step 2 included. Call
+
+   `jsc-hooks/tools/report-status.sh skill-end jsc-gitea:html-style {status} {exit code} [detail]`
+
+   `{exit code}` is the exit code of whatever decided the outcome, and `0` when nothing failed. `{detail}` is one short line, no more than 200 characters. **If the script is not on this machine, skip this step in silence and finish the run as it stood** — missing infrastructure is not a failure, and a reporting call may never change what this skill returns or reports.
+
+   | status | When this skill uses it |
+   | --- | --- |
+   | `ok` | `set` exited 0 and step 6 read the pair back with the source column matching the scope that was chosen |
+   | `blocked` | The template directory is missing, so `layouts` or `styles` listed nothing. There is no name to offer and no pair to write, so the run stops before any question and the settings file is untouched |
+   | `failed` | The write itself broke: `set` returned 1 because the settings directory could not be created, 2 on a malformed call, or 4 because the layout or style has no template file. Nothing was written |
+   | `degraded` | `set` exited 0, but step 6 read back a different source than the scope chosen in step 4 — usually a project file holding the same key and winning over a global write. The pair is on disk, yet the export will still resolve to another one |
+   | `aborted` | The user stopped at one of the four questions — the kind key, the layout, the style or the scope — so nothing was written |
+
+   Completion condition: exactly one `skill-end` line was recorded for this run, or the script was absent and the run finished without it.
 
 ## Rules