Add MUDCraft Minecraft server infrastructure

- Purpur 1.21.4 server via itzg/docker-minecraft-server (java21)
- StatefulSet with 3 PVCs: worlds (20Gi), plugins (5Gi), logs (5Gi)
- Aikar G1GC JVM flags, 6GB heap (sized for Legion's 15GB RAM)
- Postgres: mudcraft database + user in existing platform/postgres
- RCON secret + DB password via ExternalSecret → Vault
- Traefik TCP entrypoint on port 25565 for mudcraft.nook.family
- mudcraft namespace via Terraform
- Argo CD app watching k8s/mudcraft/

servers/legion/apps/mudcraft.yaml

@@ -0,0 +1,20 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: mudcraft
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: http://10.43.1.53:3000/will/infrastructure.git
+    targetRevision: main
+    path: servers/legion/k8s/mudcraft
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: mudcraft
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+      - CreateNamespace=true