Add Ansible playbooks, inventory, and scripts for initial setup

Includes:
- `bootstrap-debian13.yml` for system setup and user configuration
- `firewall-iptables.yml` for IPv4 firewall management
- `run-playbook.sh` and `check.sh` scripts for playbook execution and validation
- `inventory.ini` for host definitions
- Template for iptables rules at `templates/iptables/rules.v4.j2`
- `README.md` with usage instructions

README.md

@@ -0,0 +1,6 @@
+## General
+#### Syntax Check
+ansible-playbook -i inventory.ini bootstrap-debian13.yml --syntax-check -vvvv
+
+# Step 1
+ansible-playbook -i inventory.ini bootstrap-debian13.yml