Two features:
- Granola-style live notes redesign: ManualNotes/SegmentNote are the IPC +
on-disk shape of manual_notes.json (freeform notes typed during
recording, plus per-moment annotations anchored by timestamp).
- Calendar bloat fix: Settings.pst_import_range_days persists how far back
a PST import should go (None = full history), applied to both a manual
import and the pst_auto_sync startup re-import.