New comment-mode input:
- 'sticky' (default, backwards-compat): update the existing marker comment
in place — same behavior as before
- 'repost': minimize all prior marker comments as OUTDATED (GitHub's native
hide-comment UI via GraphQL minimizeComment mutation) and post a fresh
comment at the bottom of the conversation
Useful for /stageblog where each staging should produce a visible new
comment while keeping history collapsible rather than lost.
Both deploy and cleanup accept the input and must match. cleanup in repost
mode minimizes all prior comments and posts a final cleanup note.
Also:
- Extract both comment scripts to sibling comment.js files (same pattern as
slash-commands/main.js) — the inline YAML scripts were getting long
- Paginate listComments (was only fetching the first 30)
