sickdays: per-date pool, no cap or reason, add/remove today or later only,
import_legacy for the migration. LWW state flip per date (no tombstones),
Firebase RTDB sickdays-sync/devices/<uuid>/sick_days.json, HMAC audit trail.
Readers fail closed (unreadable pool = not sick, logged); writers refuse a
corrupt pool. Free-day cross-check via a lazily imported freedays predicate.
earned_time: resolve(..., sick=True) floors the final shutdown at 20:00
(capped at the ceiling); gaming, terms and base unchanged. Result dataclasses
moved to _resolution.py for the line cap.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Xfj1sxKH9VBPqpcAni8Jry
