refactor: modularize the configuration

chore: remove unnecessary code, use modules instead of imports, split files

fix: put correct data dir to syncthing

feat: add new laptop phobos

chore: move semi-secrets to separate flake

chore: update to nixos-unstable

feat: add laptop to syncthing

feat: add current desktop to syncthing devices

feat: update syncthing directories to match userDirs

fix: add necessary firewall syncthing settings

feat: add syncting service