cb37b1deea
Extends Clock_IncMS()'s existing sec->min->hour cascade to also roll day->month->year (with leap-year Feb 29 via Days_In_Month()), and adds Clock_RecalcWeekday() computing current_weekday via Zeller's congruence whenever the date changes, rather than trusting PCF8563's own weekday register (which would drift if the date is edited manually). Verified the formula against 2026-07-31, a known Friday.