- overnight.ts: Yjs helpers to set/clear/check overnight flag on waypoints
- compute-days.ts: Pure function splitting routes into DayStage[] at day breaks
- use-days.ts: Reactive hook mapping Yjs state into computeDays() input
- GPX generate: emit <type>overnight</type> for isDayBreak waypoints
- GPX parse: recognize <type>overnight</type> and set isDayBreak on waypoints
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
