Add compact prompt-defense baselines to active ECC prompt surfaces and copied CLAUDE examples. AgentShield prompt-defense findings are now zero; local tests passed 2366/2366.
Translate English prose inside plain text code blocks (```text, ```)
across ja-JP documentation to Japanese, following the same approach
as PR #753 (zh-CN translation).
Translated content includes:
- Output template labels and status messages
- Folder tree inline comments
- CLI workflow descriptions
- Error/warning message examples
- Commit message templates and PR title examples
Technical identifiers, file paths, and actual code remain untranslated.
