feat(sso): wire Keycloak SSO end-to-end across all apps

New stack:
- stacks/oauth2-proxy/ — per-app sidecars (mlflow, portainer, rabbitmq)
  that gate vhosts via nginx auth_request against Keycloak's wbd realm.

Native OIDC wired into:
- grafana       (generic_oauth, role-attribute-path → Admin/Editor/Viewer)
- jupyterhub    (oauthenticator.GenericOAuthenticator)
- node-red      (passport-openidconnect; in-memory state store + users()
                 resolver because adminAuth doesn't expose req.session)
- jenkins       (oic-auth plugin via JCasC; matrix-auth for authz; setup
                 wizard suppressed; custom image with plugins.txt)

Infra fixes uncovered while bringing the above online:
- nginx-proxy: bump proxy_buffer_size to 16k so oauth2-proxy callbacks
  don't 502 on the JWT-bearing Set-Cookie header.
- nginx-proxy: add `resolver 127.0.0.11 valid=30s` so service names
  re-resolve after sidecar recreates (was cross-wiring oauth2-proxy
  upstreams after restart).
- jupyterhub: pass --allow-root to the singleuser spawner (hub runs as
  root inside its container; jupyter-server refused root without flag).
- jupyterhub Dockerfile: install jupyterlab + notebook so
  SimpleLocalProcessSpawner has something to launch.
- node-red Dockerfile: install passport-openidconnect into the image
  so settings.js can require() it.
- portainer: pre-seed local admin via --admin-password=<bcrypt-hash>
  so the 5-minute "no admin → lockout" timer can never trigger.
- deploy.sh: restore executable bit (was 644 in repo).

Admin/viewer policy:
- Created realm role `app-admin` in keycloak wbd realm.
- Grafana maps app-admin → Admin (default Viewer).
- Jenkins matrix-auth grants r.de.ren Overall/Administer, authenticated
  users get Overall/Read + Job/Read + View/Read.
- Node-RED: NODERED_ADMIN_USERS env list → permissions "*", others
  ["read"]. (TODO: switch to app-admin realm role.)
- JupyterHub: JUPYTERHUB_ADMIN_USERS env list. (Same TODO.)
- Gitea: r.de.ren pre-created as local admin; OIDC auto-links via email.

Docs:
- README, cloud/README, stacks/oauth2-proxy/README, and per-stack
  READMEs updated to reflect the new state and remove resolved TODOs.
- cloud/.env.example gains all the new OIDC client + cookie-secret keys.
- cloud/README documents the full kcadm realm bootstrap, including the
  hardcoded-audience mapper and post-logout redirect URIs that are
  non-obvious gotchas.

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

stacks/node-red/README.md

@@ -2,7 +2,36 @@
 
 Node-RED flow editor + runtime. Used at both cloud and edge.
 
-- **UI**: internal port 1880 → reverse-proxied at `/node-red` (or subdomain)
+- **Hostname**: `flow.wbd-rd.nl`
 - **Networks**: `app`
 - **Volumes**: `node-red-data` (flows + credentials)
-- **TODO**: Keycloak OIDC integration, preinstalled module list, EVOLV nodes installation
+- **Image**: built locally (`cloud-node-red:4.1`) — upstream Node-RED + `passport-openidconnect`. See `Dockerfile`.
+- **Config**: `config/settings.js` (mounted to `/data/settings.js`)
+
+## Auth
+
+The **editor** (not the runtime HTTP-in / dashboard nodes) is gated by Keycloak OIDC via `passport-openidconnect`.
+
+### Implementation notes
+
+Node-RED's `adminAuth.type=strategy` mode doesn't give the passport strategy access to `req.session`, so we can't use passport-openidconnect's default `SessionStore`. `config/settings.js` provides an **in-memory state store** keyed by a random handle (10-minute TTL) — handles are issued at the `/auth/strategy` redirect and consumed at the callback. State survives across the OAuth round trip without needing express-session.
+
+Verify returns `{username: <preferred_username>}`; the `adminAuth.users(username)` resolver then expands that to a Node-RED user object with permissions.
+
+### Permissions
+
+Set `NODERED_ADMIN_USERS` (comma-separated usernames or emails) in `.env`:
+
+| User | permissions |
+|---|---|
+| listed in `NODERED_ADMIN_USERS` | `"*"` (full editor) |
+| any other authenticated realm user | `["read"]` (can view flows, cannot deploy) |
+
+Switching this to a Keycloak `app-admin` realm-role check is a TODO.
+
+## TODO
+
+- Switch admin lookup from env-list to `app-admin` realm role
+- Gate runtime HTTP-in / dashboard routes with `httpNodeAuth` if/when we expose them publicly
+- Preinstalled module list (`packages.json`) — mqtt, influxdb, postgres clients
+- Set `credentialSecret` in settings.js (currently auto-generated; rotating it forces re-entering creds)