feat(changelog): activate per-day bumper + RSS via Option C (forward-only)
Graduates the WIP scaffold from 8984a838 to a working pipeline:
- package.json: add `changelog:bump` script
- CHANGELOG.md: insert `<!-- last-bumped: 2922b5ec -->` marker (current main),
plus a boundary note documenting the two-format coexistence — pre-2026-04-29
per-day archival sections stay as-is, all new entries go into per-week
wrappers above them. RSS deliberately ignores the archival format.
- docs/feed.xml: regenerated by the new per-bullet RSS script. Empty for now
because no new-format sections exist yet — the first push that runs
`yarn changelog:bump` will populate the file from clustered commits.
Format choice: Option C from project_changelog_rss_workflow.md. Trade-off
accepted: existing archival sections remain rich + checkbox-detailed in the
file, but they don't show up in RSS. Discord audience gets the rolling
7-day per-bullet stream the new format was designed for; archival reading
still works in CHANGELOG.md.
Smoke test 2026-04-29:
- `yarn changelog:bump --dry-run --since 091e2a43` clusters correctly,
skips chore/test/docs(changelog), produces well-formed bullets.
- `yarn rss` against a synthetic new-format CHANGELOG produces valid RSS.
- `yarn changelog:bump --dry-run` against current state correctly reports
"No commits in 2922b5ec..main; nothing to bump."
- `yarn rss` regenerates feed.xml as empty (0 items, 7-day window) — as
designed under Option C.