Migration 92_cad_bulk_layers.sql fails on deploy with:
ERROR: relation "cad_buildings_pkey" already exists
CONTEXT: ALTER INDEX cad_buildings_new_pkey RENAME TO cad_buildings_pkey
Root cause: K.1 renamed cad_buildings → cad_buildings_old_apr26, but PG
does NOT auto-rename the backing PK index on table rename. The legacy
cad_buildings_pkey index is still attached to cad_buildings_old_apr26.
K.3 then tries to rename cad_buildings_new_pkey to the same name → collision.
Fix: add an explicit `ALTER INDEX IF EXISTS cad_buildings_pkey RENAME TO
cad_buildings_old_apr26_pkey` BEFORE the new rename. Idempotent (IF EXISTS).
Migration 92 was rolled back in last 3 deploy attempts (not in
_schema_migrations), so this edit will re-apply cleanly on next deploy.
