vUsuariosDirectory: lateral aggregates compute for all 758 users before LIMIT

Admin usuarios directory list query (MARS-555, migration 085): EXPLAIN ANALYZE shows 1.6s to return top 50 because the view's 2 correlated LATERAL aggregate subqueries (roles, comisiones) compute for all 758 rows before the caller's ORDER BY/LIMIT trims it -- LIMIT can't push into the lateral aggregation. Not an index gap; needs restructuring (limit base vUsers set before joining laterals). db-mars-cc confirmed root cause via EXPLAIN ANALYZE, defers fix ownership -- low traffic (93 calls), not urgent.