fix(log): 補齊稽核缺失並修掉護欄失效

What：依 jsc-meta:skill-check 的稽核結果修正技能與工具——補上每個步驟的可檢核完成條件、
把留在內文的標準輸入輸出流程下放 tools/、修正查表與退碼路由造成的誤判。

Why：稽核發現這些缺失會讓技能在實際執行時走錯分支或靜默通過。
完成條件缺漏是最常被違反的一項；退碼誤判與查表錯誤則會讓良性狀況被當成失敗。

How：逐項對照 references/guidelines.md 的審核檢查清單修正，新增的工具都有
documented exit codes，並以真實執行驗證每條路徑。

Who：jsc-meta:skill-check 例行稽核（2026-08-25）。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

skills/learn/SKILL.md

@@ -10,7 +10,7 @@ Close the loop on skill runs: record what a run taught you, consult it before th
 ## Target pages
 
 - Directory page: `LEARN_CONTENTS`. Content page: `LEARN_{HASH}`, one page per repository.
-- Compute `{HASH}` from `{owner}/{repo}` with `jsc-gitea/tools/hash-id` (shared wiki hash rule: first 8 uppercase SHA-1 hex chars; `H` plus the first 7 chars when the raw hash starts with `0-9`, `A`, `B`, or `C`).
+- Compute `{HASH}` from `{owner}/{repo}` with `jsc-gitea/tools/hash-id`.
 - Wiki repo resolution: `JSC_WIKI_REPO_LEARN` first, then `JSC_WIKI_REPO`. Inspect the inherited shell environment variables first; ask the user per the `jsc-ask:ask` rules only when neither resolves. Never borrow another type's `JSC_WIKI_REPO_{TYPE}`.
 - All wiki reads and writes go through `jsc-gitea:wiki`.