Add Proxmox group_vars to disable UFW

Proxmox uses its own firewall (pve-firewall) and doesn't need UFW.
This prevents accidental lockout of web UI (port 8006).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

group_vars/proxmox.yml

@@ -0,0 +1,14 @@
+---
+# Proxmox-specific variables
+
+# Disable firewall on Proxmox (uses its own iptables rules)
+common_firewall_enabled: false
+
+# Or if you want UFW, allow these ports:
+# common_firewall_allowed_ports:
+#   - "22/tcp"
+#   - "8006/tcp"        # Web UI
+#   - "5900:5999/tcp"   # VNC
+#   - "3128/tcp"        # SPICE proxy
+#   - "5404:5405/udp"   # Corosync cluster
+#   - "111/tcp"         # rpcbind