fix: use TF_VAR_ prefix for token credentials

- Restore pm_api_token_id and pm_api_token_secret variables
- Use TF_VAR_pm_api_token_id and TF_VAR_pm_api_token_secret env vars
- This is the standard Terraform way to pass variables via environment

terraform/main.tf

@@ -8,8 +8,10 @@ terraform {
 }
 
 provider "proxmox" {
-  pm_api_url      = var.pm_api_url
-  pm_tls_insecure = true
+  pm_api_url          = var.pm_api_url
+  pm_api_token_id     = var.pm_api_token_id
+  pm_api_token_secret = var.pm_api_token_secret
+  pm_tls_insecure     = true
 }
 
 resource "proxmox_vm_qemu" "alpacas" {