Personal NixOS configuration as a flake.

• flake.nix — inputs + flake-parts entry point
• parts/ — flake-parts modules (hosts, formatter, checks, dev shell)
• hosts/<name>/ — host-specific config + generated hardware
• modules/nixos/ — one-concern system modules
• modules/home/ — one-concern Home-Manager modules
• lib/mkHost.nix — host factory (wires Home-Manager as a NixOS module)

sudo nixos-rebuild switch --flake .#pavg15

nix develop      # or: direnv allow
nix fmt          # format
nix flake check  # lint + build checks