Restore reportedPracticeDate required + drop today-default (reverse MARS-509 over-relaxation) + add to EVO-66 flash set

Elazar 2026-07-19: a práctica must never have a blank/defaulted date. MARS-509 dropped native required on reportedPracticeDate AND left the server defaulting a blank to today (getTodayArgentinaDateString), which silently stamps a wrong date. Fix: (1) reportedPracticeDate REQUIRED again — block empty submit via inline Spanish cue, no native popup; (2) remove server today-default, reject null (MISSING_DATE) on create+edit actions; (3) add date to the MARS-514/EVO-66 preventive FlashField set (now sexo+dni+date). Keeps the required-field-gets-visual-cue fleet principle. fechaNacimientoPaciente untouched (separate Q). Possible follow-on: backfill/flag rows already defaulted-to-today (db pulling count). Class-S code; the backfill leg if any is separate + may need Elazar go.