* fix(#2660): capture prose after label in extractOneLinerFromBody
The regex `\*\*([^*]+)\*\*` matched the first bold span, so for the new
SUMMARY template `**One-liner:** Real prose here.` it captured the label
`One-liner:` instead of the prose. MILESTONES.md then wrote bullets like
`- One-liner:` with no content.
Handle both template forms:
- Labeled: `**One-liner:** prose` → prose
- Bare: `**prose**` → prose (legacy)
Empty prose after a label returns null so no bogus bullets are emitted.
Note: existing MILESTONES.md entries generated under the bug are not
regenerated here — that is a follow-up.
Closes#2660
* fix(#2660): normalize CRLF before one-liner extraction
Windows-authored SUMMARY files use CRLF line endings; the LF-only regex
in extractOneLinerFromBody would fail to match. Normalize \r\n and \r
to \n before stripping frontmatter and matching the one-liner pattern.
Adds test case (h) covering CRLF input.
