Remove Trino: Superset reads fuel-db directly as fuel_ro (PD-14)

trino/ deleted; the role trino_ro becomes fuel_ro, its password read from a
secret file at connect time; dashboards' SQL and column list for PostgreSQL;
the Compose project is renamed petrolyst, with volumes pinned to their old
names. AGENTS.md points to the architecture context. Not deployed: the next
deploy needs README's one-time steps first.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

deploy/deploy.sh

@@ -44,7 +44,7 @@ resolve_artifacts() {
   fi
   chmod -R a-w "$release"
   load_artifacts "$release"
-  log "artifacts: superset $SUPERSET_IMAGE_TAG, trino config $TRINO_CONFIG_HASH, traefik config $TRAEFIK_CONFIG_HASH"
+  log "artifacts: superset $SUPERSET_IMAGE_TAG, traefik config $TRAEFIK_CONFIG_HASH"
 }
 
 # prepare_fuel_monitoring <release>: before anything live changes, build the