Sign-in by customer: realm petrolyst, row rules, guest role (PD-21)

Keycloak import for realm petrolyst: two clients, petrolyst with MFA for
Superset and Traefik, petrolyst-app password only. It lists only
app.petrolyst.com and traefik.petrolyst.com, and no customer names, as this
repository is public. public.v_operator shows each customer's group. Dashboards
overview and site, role Petrolyst Guest, filtered by row. Superset refuses a
user with no mapped role. The realm travels with the release: each release's
compose files name their realm and secret file, and a rollback needs only its
target's secret. Not deployed.

Checks earlier on this content: tests/run.sh 109 of 109 and read-only, dashboards
import twice, column drift 0, compose config on old and new trees, the secret
check on a scratch folder, a rehearsal on a throwaway Keycloak 26.4. Never a real
deploy or rollback; shellcheck not installed today, clean when last run. Codex
inspected once; its fixes are not re-inspected, on the owner's word.

Bands: persistence, Superset. Rules: 1, 2, 3, 6, 14.

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

stacks/fuel-monitoring/compose.yaml

@@ -5,7 +5,7 @@
 name: petrolyst
 
 x-superset-env: &superset-env
-  KEYCLOAK_REALM_URL: ${KEYCLOAK_REALM_URL:-https://iam.thedigitalbridge.io/realms/thedigitalbridge}
+  KEYCLOAK_REALM_URL: ${KEYCLOAK_REALM_URL:-https://iam.thedigitalbridge.io/realms/petrolyst}
 
 x-superset: &superset
   image: fuel-superset:${SUPERSET_IMAGE_TAG:?SUPERSET_IMAGE_TAG unset - run through deploy/deploy.sh}
@@ -158,4 +158,4 @@ secrets:
   fuel_db_ro_password:
     file: ${PETROLYST_ROOT:-/opt/petrolyst}/secrets/fuel-monitoring/fuel_db_ro_password
   keycloak_petrolyst_client_secret:
-    file: ${PETROLYST_ROOT:-/opt/petrolyst}/secrets/shared/keycloak_petrolyst_client_secret
+    file: ${PETROLYST_ROOT:-/opt/petrolyst}/secrets/shared/keycloak_petrolyst_realm_client_secret