Phase 4 group scheduling: schema migration adds group_id to schedules with
CHECK constraint, scheduler evaluates group+device schedules with priority,
group deletion converts schedules to per-device copies. Dashboard gets
playlist assignment dropdown and current playlist label on group headers.
Player persists audio unlock state in localStorage so version reloads
don't lose audio on unattended displays.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
ScreenTinker - open source digital signage management software.
MIT License, all features included, no license gates.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>