Onboard Crafty Controller (Minecraft panel) with Keycloak-gated web UI

Add Crafty Controller 4 (registry.gitlab.com/crafty-controller/crafty-4:4.10.8)
as a platform component: a web panel that runs Java + Bedrock Minecraft servers as
subprocesses in one pod + a 20Gi Longhorn PVC (mounted 5x by subPath).

Auth = Option B (per-app oauth2-proxy reverse-proxy sidecar), since Cilium 1.16.5
cannot do ext_authz on the shared Gateway:
- oauth2-proxy v7.8.1 sidecar (:4180) reverse-proxies to Crafty's self-signed HTTPS
  UI (127.0.0.1:8443), gated to Keycloak homelab realm group platform-admins.
- Confidential `crafty` client provisioned live via kcadm + captured in the realm
  import; client secret + cookie secret via SOPS/age (mirrored in realm-clients).

- Web UI: HTTPRoute crafty.home.keithjackson.dev -> Service :80 -> sidecar :4180.
- Game ports: Cilium L2 LoadBalancer on VIP 192.168.1.55 (next free after .53/.54),
  starter set TCP 25565-25567 (Java) + UDP 19132-19134 (Bedrock), NOT auth-gated.
- fsGroup:0 / runAsGroup:0 / runAsUser:1000 for the image's crafty:root identity on
  the root:root Longhorn PVC (the seerr fsGroup lesson).
- Own non-gating Flux tier clusters/base/crafty.yaml (dependsOn platform-config,
  wait:false) + sops-decryption patch in clusters/dev — a leaf UI must never gate
  the platform.
- Explicit default-deny NetworkPolicy + CiliumNetworkPolicies (platform namespace,
  not app-namespace, so Kyverno does not auto-generate the baseline).

make -C ci gate green; kustomize build of platform/crafty, clusters/base,
clusters/dev clean.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

platform/keycloak/keycloak-realm-clients.sops.yaml.example

@@ -38,3 +38,5 @@ stringData:
   grafana-client-secret: REPLACE-ME
   oauth2-proxy-client-secret: REPLACE-ME
   headlamp-client-secret: REPLACE-ME
+  # Mirror into platform/crafty/crafty-oauth2-proxy-credentials.sops.yaml (key: client-secret).
+  crafty-client-secret: REPLACE-ME