feat: Add Kubernetes manifests for NetHack server

- Creates Kubernetes deployment, service, and PVC manifests to run a multiplayer NetHack server.
- Uses the pre-built matsuu/nethack-server:latest image.
- Configures the service to expose port 4000 externally and correctly route traffic to the container's port 23.
- Adds a .gitignore file to exclude temporary directories.

GEMINI.md

@@ -0,0 +1,47 @@
+# GEMINI.md - NetHack Multiplayer Server su Kubernetes
+
+namespace: nethack
+
+# Deployment del server NetHack
+deployment:
+  name: nethack-server
+  replicas: 1
+  labels:
+    app: nethack
+  container:
+    image: matsuu/nethack-server:latest
+    name: nethack
+    ports:
+      - containerPort: 4000
+    env:
+      - name: DGL_PORT
+        value: "4000"
+      - name: DGL_HOST
+        value: "0.0.0.0"
+    volumeMounts:
+      - name: nethack-data
+        mountPath: /opt/nethack/data
+
+  volumes:
+    - name: nethack-data
+      persistentVolumeClaim:
+        claimName: nethack-pvc
+
+# PersistentVolumeClaim per salvataggi e configurazioni
+pvc:
+  name: nethack-pvc
+  accessModes: [ "ReadWriteOnce" ]
+  resources:
+    requests:
+      storage: 1Gi
+
+# Service ClusterIP interno
+service:
+  name: nethack-service
+  type: LoadBalancer
+  ports:
+    - port: 4000
+      targetPort: 4000
+      protocol: TCP
+  selector:
+    app: nethack