When a VM has firewall=1, Proxmox inserts a fwbr bridge and iptables
POSTROUTING fires at the bridge step (OUT=fwbrNNNi0) rather than at
vmbr0. The MASQUERADE rule (-o vmbr0) never matches, so the VM loses
internet access.
Adds an idempotent task to the proxmox_host role that strips
firewall=1 from VM 105's net0 config whenever the playbook runs.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>