Hide non-required fields + require Endodoncia I fields for Endodoncia I students

Client-accepted quote item 3 (2026-08-03). Per-materia práctica form field visibility for Endodoncia I: hide fields not relevant to Endo I, and require radiografía photo, número de pieza, lima, calibre del cono, obturación. Depends on the materia dimension (already shipped, d5d85d5) and the período/comisión setup (quote item 1, db lane) to gate on. numeroHistoriaClinica is explicitly OUT of scope here -- stays as-is, tracked separately in MARS-534/MARS-331. Touches practica-form.tsx (create) and mi-cursada/[id]/editar/edit-form.tsx (edit) -- same two-form pattern as every other práctica-field change this cycle (see SOP-MARS-39 / MARS-607: both forms need the same rule or one silently diverges from the other).