proxmox: add VM automation with OpenTofu and Ansible

Add automated workflow for building and deploying NixOS VMs on Proxmox including template2 host configuration, Ansible playbook for image building/deployment, and OpenTofu configuration for VM provisioning with cloud-init.

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

hosts/template2/default.nix

@@ -0,0 +1,9 @@
+{ ... }:
+{
+  imports = [
+    ./hardware-configuration.nix
+    ./configuration.nix
+    ./scripts.nix
+    ../../system/packages.nix
+  ];
+}