fix(docs): add genieai role to PG migration password reset
Root Cause
UPGRADE.md step 7b only resets kong and keycloak roles after PG 13→16 migration.
pg_dumpall restores the genieai superuser's OLD password from the dump, which mismatches POSTGRES_PASSWORD in the deployment .env. This breaks postgres-init (exit 2) and cascades to kong-migrations, kong-config, reranker, retriever, dataprep.
Fix
Add ALTER ROLE genieai WITH PASSWORD '<POSTGRES_PASSWORD>' to step 7b.
Reset ALL roles: genieai (superuser), kong, keycloak.
Verification
Production deploy: resetting genieai password + restarting postgres-init → Complete. Cascade services started.