Initial minecraft role

Paper/Java via itzg/minecraft-server in docker compose; whitelist and ops synchronized from Ansible, RCON on localhost only, explicit EULA flag.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

templates/opt/minecraft/docker-compose.yml.j2

@@ -0,0 +1,16 @@
+name: minecraft
+services:
+  server:
+    image: {{ minecraft_image }}:{{ minecraft_image_tag }}
+    restart: unless-stopped
+    env_file:
+      - .env
+    ports:
+      - "{{ minecraft_port }}:25565"
+      - "127.0.0.1:{{ minecraft_rcon_port }}:25575"
+    volumes:
+      - {{ minecraft_data_location }}:/data
+    # give the server time to save the world on stop
+    stop_grace_period: 60s
+    tty: true
+    stdin_open: true