CI / build-test (push) Successful in 1m11s
Introduce a Calendar in Core that turns scaled clock time into whole in-game days plus a fraction-of-day, with a configurable SecondsPerDay. Pausing or changing TimeScale slows or stops it automatically. Pure read-side and deterministic, registered via context.UseCalendar(...), mirroring GameSpeed. Covered by xUnit tests; docs updated. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>