Add rominasseron@gmail.com as Endo I test student (Seron Estudiante Prueba)

Elazar direct ask: new Gmail-login student user for Endodoncia I, distinct from her existing institutional-login row. Created 27ec1069-27e6-425c-9a85-bc98e6369c51 (rominasseron@gmail.com, 'Seron Estudiante Prueba', role alumno, createdVia admin_manual) -- romina.seron@odontologia.uba.ar row untouched. Enrolled comisión A - Endo 1 (028905a4-..., 57 students, most-enrolled Endo I comisión, query-verified). Assigned María Eugenia Miyashiro (fdf0a84f-...) -- sole principal JTP, unanimous match with all 57 existing students' assignedTeacherUserId. Welcome email sent via /api/internal/send-email (eventId ea64b97e) replicating dispatchWelcomeEmail since the row bypassed the normal server action.