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>

flake.nix

@@ -172,6 +172,22 @@
             sops-nix.nixosModules.sops
           ];
         };
+        template2 = nixpkgs.lib.nixosSystem {
+          inherit system;
+          specialArgs = {
+            inherit inputs self sops-nix;
+          };
+          modules = [
+            (
+              { config, pkgs, ... }:
+              {
+                nixpkgs.overlays = commonOverlays;
+              }
+            )
+            ./hosts/template2
+            sops-nix.nixosModules.sops
+          ];
+        };
         http-proxy = nixpkgs.lib.nixosSystem {
           inherit system;
           specialArgs = {