docs: update terraform README for cloud-init refactoring

Remove mention of .generated/ directory and clarify that cloud-init.tf
manages all cloud-init disks, not just branch-specific ones.

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

terraform/README.md

@@ -198,11 +198,10 @@ deployment_summary = {
 - `main.tf` - Provider configuration
 - `variables.tf` - Variable definitions and defaults
 - `vms.tf` - VM definitions and deployment logic
-- `cloud-init.tf` - Custom cloud-init configuration for branch-specific bootstrap
+- `cloud-init.tf` - Cloud-init disk management (SSH keys, networking, branch config)
 - `outputs.tf` - Output definitions for deployed VMs
 - `terraform.tfvars.example` - Example credentials file
 - `terraform.tfvars` - Your actual credentials (gitignored)
-- `.generated/` - Auto-generated cloud-init files (gitignored)
 - `vm.tf.old` - Archived single-VM configuration (reference)
 
 ## Notes