fix(terraform): align VM config with real Proxmox state

terraform/README.md

@@ -56,11 +56,27 @@ terraform output -json kubeconfig | jq -r '.homelab' > ~/.kube/config
 terraform output -json talosconfig | jq -r '.homelab' > ~/.talos/config
 ```
 
+## Talos Factory Image
+
+The ISO is built via [Talos Image Factory](https://factory.talos.dev) with a custom schematic that includes:
+- **QEMU guest agent** (`qemu-guest-agent` system extension)
+- **i915** Intel iGPU firmware extension
+
+**Schematic ID:** `aa948be975ffec096205160edd988ee6d949d72c20a39ca5844fc0a2a3fc8415`
+
+**Installer reference:** `factory.talos.dev/metal-installer/aa948be975ffec096205160edd988ee6d949d72c20a39ca5844fc0a2a3fc8415:v1.12.5`
+
+Download URL pattern:
+```
+https://factory.talos.dev/image/<schematic-id>/<version>/metal-amd64.iso
+```
+
 ## Notes
 
 - The Talos ISO resource has `prevent_destroy = true` to avoid accidental re-download
 - Control plane node has `allowSchedulingOnControlPlanes = true` (single-node cluster)
 - State files (`terraform.tfstate`, `terraform.tfstate.backup`, `terraform.tfvars`, `talosconfig`) are gitignored
+- `gpu_mapping` is optional per cluster; omit it to skip PCI passthrough
 
 ## Next Steps