Expose minecraft server over TCP via MetalLB

Minecraft Java Edition uses raw TCP on port 25565, not HTTP. The previous
ClusterIP Service + HTTP Ingress (Traefik 80/443) could not carry TCP 25565
traffic, so minecraft.rogi.casa:25565 was unreachable.

- Change Service to LoadBalancer with fixed IP 10.88.20.103 (dmz-pool),
  matching the pihole-dns pattern, so port 25565 is exposed directly.
- Remove the dead HTTP ingress (it routed HTTP to a TCP game port).

minecraft-server/minecraft-server.yaml

@@ -12,10 +12,12 @@ metadata:
   labels:
     app: minecraft-server
 spec:
-  type: ClusterIP
+  type: LoadBalancer
+  loadBalancerIP: 10.88.20.103
   ports:
     - name: minecraft
       port: 25565
       targetPort: 25565
+      protocol: TCP
   selector:
     app: minecraft-server