feat(cloud): short function-based subdomains + harden keycloak with postgres

Subdomain rename (Versio side keeps original tool-named hostnames)
- nginx vhosts updated:
    grafana   -> dash.wbd-rd.nl
    gitea     -> git.wbd-rd.nl
    keycloak  -> auth.wbd-rd.nl
    node-red  -> flow.wbd-rd.nl
    mlflow    -> ml.wbd-rd.nl
    jupyter   -> hub.wbd-rd.nl
    portainer -> ops.wbd-rd.nl
    rabbitmq  -> mq.wbd-rd.nl
    jenkins   -> ci.wbd-rd.nl
    mqtt      -> mqtt.wbd-rd.nl   (no Versio conflict assumed)
- nginx-proxy README: bootstrap cert -d list + DNS A-record prereqs updated
- cloud/.env.example: GITEA_ROOT_URL, GRAFANA_ROOT_URL, KEYCLOAK_HOSTNAME

Function-based names are tool-agnostic (a Grafana -> Kibana swap leaves
dash.wbd-rd.nl meaningful) and avoid one-off "*2" suffixes.

Keycloak hardening
- Switch backend from bundled file storage to postgres (keycloak DB
  already provisioned by sql/config/init.d/01-databases.sh).
- KC_HOSTNAME=auth.wbd-rd.nl, KC_PROXY_HEADERS=xforwarded for nginx
  reverse-proxy posture; KC_HTTP_ENABLED=true since nginx terminates TLS.
- Added KC_HOSTNAME_STRICT, KC_HEALTH_ENABLED, KC_METRICS_ENABLED.
- Service joins app + mgmt + data networks (data needed for postgres).
- Mounted config/realms/ for realm-as-code (kc.sh import) — TODO to
  populate once realm + clients are designed.
- README documents the recommended realm structure (wbd realm, one
  client per app with redirect URIs) and the oauth2-proxy approach
  for apps without native OIDC (mlflow, portainer-CE).

cloud
- Uncomment keycloak include in cloud/compose.yml.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

stacks/keycloak/README.md

@@ -1,7 +1,62 @@
 # keycloak
 
-Identity provider for SSO across grafana, node-red, gitea, jenkins, portainer.
+Identity provider for SSO across all R&D services. **Cloud-only** for now (edges get their own realms once we cover the edge layer).
 
-- **Networks**: `app` (OIDC endpoints for relying apps) + `mgmt` (admin console)
-- **Storage**: stub uses bundled file storage; move to `sql` stack before production
-- **TODO**: realm + client provisioning (kc.sh or terraform-keycloak), session/token lifetimes, theme branding
+- **Public hostname**: `auth.wbd-rd.nl` (reverse-proxied via nginx-proxy at HTTPS → backend HTTP 8080)
+- **Networks**: `app` (OIDC endpoints for relying-party apps) + `mgmt` (admin console) + `data` (postgres backend)
+- **Backend**: postgres `keycloak` database in `sql` stack — provisioned automatically by `sql/config/init.d/01-databases.sh` on first start
+- **Volume**: `keycloak-data` (themes, providers, realm exports)
+
+## First-run bootstrap
+
+`KC_BOOTSTRAP_ADMIN_USERNAME` + `KC_BOOTSTRAP_ADMIN_PASSWORD` create the master-realm admin on first start. **Change the password immediately after first login** via the admin console.
+
+After deployment:
+
+```bash
+# 1. Bring it up (sql must be running first)
+cd /mnt/d/gitea/RnD/infra/cloud
+docker compose up -d sql            # if not already up
+docker compose up -d keycloak
+
+# 2. Watch logs until you see "Keycloak <version> on JVM started"
+docker compose logs -f keycloak
+
+# 3. Browse  https://auth.wbd-rd.nl/  → admin console
+#    (until cert is bootstrapped, https://<cloud-host>:9443 portainer can show logs)
+```
+
+## Realm + clients (TODO — design before deploy day 2)
+
+**Recommended structure**: one realm `wbd` containing all R&D apps as separate clients.
+
+| Client ID | App | Redirect URI | Flow |
+|---|---|---|---|
+| grafana | Grafana | `https://dash.wbd-rd.nl/login/generic_oauth` | code |
+| gitea | Gitea | `https://git.wbd-rd.nl/user/oauth2/keycloak/callback` | code |
+| node-red | Node-RED | `https://flow.wbd-rd.nl/auth/strategy/callback/` | code |
+| jenkins | Jenkins | `https://ci.wbd-rd.nl/securityRealm/finishLogin` | code |
+| jupyterhub | JupyterHub | `https://hub.wbd-rd.nl/hub/oauth_callback` | code |
+| mlflow | MLflow (via oauth2-proxy) | `https://ml.wbd-rd.nl/oauth2/callback` | code |
+| portainer-ce | Portainer (via oauth2-proxy) | `https://ops.wbd-rd.nl/oauth2/callback` | code |
+
+Apps **without native OIDC** (mlflow, portainer-CE) sit behind an `oauth2-proxy` sidecar that nginx `auth_request`s to. That's a TODO stack we'll add when we wire up mlflow / portainer SSO.
+
+## Realm-as-code
+
+Drop exported realm JSON into `config/realms/`. On first start, Keycloak imports anything in `/opt/keycloak/data/import/` if `KC_IMPORT_REALM_DIR` is set or if you run `kc.sh import` manually. Recommended workflow:
+
+1. Configure the realm by hand once in the UI
+2. `docker compose exec keycloak /opt/keycloak/bin/kc.sh export --dir /opt/keycloak/data/import --realm wbd`
+3. Commit the exported file under `stacks/keycloak/config/realms/`
+4. Subsequent fresh deploys auto-import
+
+## TODO
+
+- Realm bootstrap script (provision `wbd` realm + clients above)
+- Theme: WBD branding (logo, colors)
+- User federation (LDAP from corporate AD, if applicable)
+- 2FA policy
+- Session / token lifetimes per client
+- oauth2-proxy stack for apps without native OIDC
+- Realm export → `config/realms/wbd.json` committed