Phase 1: additive nullable actor columns on sensitive tables (DDL)

Phase 1 DDL (db-pluto-cc): add MISSING actor/lifecycle columns as NULLABLE additive to SENSITIVE tables only — practica* clinical sub-records (anestesias/antecedentes/caracteristicasPieza/complicaciones/diagnosticos/tecnicasQuirurgicas/reviews/docenteNotas), accessRequests, supportTickets/supportTicketMessages, users, lookupOptions, systemSettings. Add createdBy where absent; deletedBy where table is soft-deleted; updatedBy where table is mutated. Nullable, no backfill in this phase, non-breaking. EXEMPT (do not touch): appEvents, dbperfSnapshots, notifications, securityAlerts, emailOutbox, appEventActionClassification, userAuditLogLegacy. EVO-57 audit-trail schema program; plan authored by coder-pluto-cc from PLUTO-580 gap report (db-pluto-cc). Elazar-gated before DDL.