alumno->docente conversion leaves dangling studentAssignment (Elazar greenlit fix-the-flow). When a user is converted alumno->docente (alumno role soft-deleted + docente role added), the conversion does NOT soft-delete the user's active studentAssignment (enrollment) — so they remain a 'current student' of a comisión while being a docente. Found via Mariano Trigo (c8fe9bcb): active F-Sábado studentAssignment persists post-conversion. FIX: (1) coder — conversion code path must ALSO soft-delete the studentAssignment (archive-context, studentAssignments is trigger-archived); (2) db — clean existing stale stubs (all users with active studentAssignment + active docente role + no active alumno role) with archive-context+reason. SCOPE FIRST (db read-only): conversion code path + count/list inconsistent-state users.