- Add nixos-uconsole and nixos-hardware inputs for CM5/RPi5 support
- Create hosts/uconsole/configuration.nix with HAM radio, SDR, and security tools
- Create hosts/uconsole/hardware-configuration.nix for CM5 hardware
- Register uConsole in flake.nix nixosConfigurations
- Add uconsole host key placeholder to lib/keys.nix