Sub-ticket of MARS-19 Investigate práctica snapshot jtpUserId==ayudanteUserId: does persistPractica copy ayudanteUserId into the jtpUserId snapshot slot at creation? (303b6f3b froze Belén Montoya in BOTH slots; real JTP is Gonzalez; reviewedBy a 3rd teacher Spinosa). Quantify systemic-ness + audit persistPractica snapshot-write. Root-cause the flow — NO row patching. · mars