Split Endodoncia I vs Endodoncia II on /estadisticas (materia as reporting dimension)

Endo I and Endo II are both folded into programa=grado on /estadisticas and averaged together despite different clinical scope. Make materia the reporting dimension: db-mars adds materia to vMultiradicularStats + vConductoMeasurements + vPiezaAccidenteFacts; app replaces the programa switch with a materia switch, regroups practica denominators by materia, bumps the unstable_cache key v4->v5, carries the scope into the emailed report, and adds a materia filter to /estadisticas/clinico. Small-n: raw counts, derived percentages suppressed. Elazar decisions 2026-08-14: 1a/2a/3a/4a/5a.