handleSelectNote skipped syncNoteTitle for tabs already open (early
return). Moved sync call into handleSelectNoteWithSync so it always
runs, even when switching to an existing tab via Cmd+P. Also removes
H1 fallback from extract_title — title now comes from frontmatter or
filename only, per the title/filename contract.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>