Initial commit: DHCP whitelist service for direct link connections

Features:
- Docker-based DHCP server with MAC address whitelisting
- Binds to specific ethernet interface only
- NO DNS/gateway advertised (direct link only, not a router)
- Configurable network parameters (subnet, DHCP range, lease times)
- Systemd service integration for Arch/Manjaro
- Test environment with isolated network (172.20.0.0/24)
- Auto-configuration script to detect network settings
- Complete Makefile with management targets

Security:
- Only responds to whitelisted MAC addresses
- deny unknown-clients configuration
- Runs in Docker container for isolation

Configuration:
- Copy .example files to create your config
- interface.conf: Network interface to bind to
- whitelist.conf: Allowed MAC addresses
- network.conf: Network parameters (optional)

.gitignore

@@ -0,0 +1,18 @@
+*.swp
+*.swo
+.DS_Store
+.env
+docker-compose.override.yml
+*.log
+*.pid
+/data/
+/tmp/
+__pycache__/
+*.pyc
+.vscode/
+.idea/
+
+# User configuration files (keep examples only)
+config/interface.conf
+config/whitelist.conf
+config/network.conf