Created ADD_WORKER_NODE.md as a step-by-step checklist for adding
new worker nodes to the k3s cluster. This complements the existing
K3S_OPERATIONS.md with a focused, actionable guide.
Key features:
- Pre-flight checklist format
- Hetzner Cloud VM creation steps (console and CLI)
- SSH key requirements (cto-paperclip, silentmaxx)
- Firewall configuration verification
- Provisioning script usage
- Health verification steps
- Documentation update procedure
- Rollback instructions
- Troubleshooting guide
Created for DEV-408 (adding worker node to resolve Stalwart scheduling).
Co-Authored-By: Paperclip <noreply@paperclip.ing>
