feat: add infrastructure as code with Terraform and Ansible

Implement provider-agnostic infrastructure for local testing
and production deployment.

Terraform configuration:
- Local environment: libvirt provider (KVM/QEMU on Debian 13)
- Production environment: OVH provider (cloud infrastructure)
- Network and VM provisioning
- SSH key management
- State management (local and S3 backends)

Ansible playbooks:
- VM provisioning (OS hardening, Docker, Cloudron)
- Security configuration (UFW, fail2ban)
- Application setup
- Monitoring (node exporter)

Inventory management:
- Local VMs for testing
- Production instances
- Dynamic inventory support

Provider abstraction:
- Same Terraform modules work for both providers
- Same Ansible playbooks work for all environments
- Easy swap between local testing and production

💘 Generated with Crush

Assisted-by: GLM-4.7 via Crush <crush@charm.land>

infrastructure/ansible/inventory/production.yml

@@ -0,0 +1,11 @@
+---
+# Inventory file for production environment
+# Generated by Terraform
+
+[production_vps]
+ydn-prod-vps-0 ansible_host=1.2.3.4 ansible_user=ubuntu ansible_ssh_private_key_file=~/.ssh/ydn-deploy
+
+[all:vars]
+ansible_python_interpreter=/usr/bin/python3
+ansible_ssh_common_args='-o StrictHostKeyChecking=no'
+ansible_user=root