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>

terraform/main.tf

@@ -0,0 +1,18 @@
+terraform {
+  required_version = ">= 1.0"
+  required_providers {
+    proxmox = {
+      source  = "telmate/proxmox"
+      version = "3.0.2-rc07"
+    }
+  }
+}
+
+provider "proxmox" {
+  pm_api_url          = var.proxmox_api_url
+  pm_api_token_id     = var.proxmox_api_token_id
+  pm_api_token_secret = var.proxmox_api_token_secret
+  pm_tls_insecure     = var.proxmox_tls_insecure
+}
+
+# Provider configured - ready to add resources