Refactor to pass host vars as arguments

Remove per‑host imports across flake, modules, and profiles, exposing
needed
variables (system, printer settings, consoleKeyMap, etc.) as arguments.
Drop unused printEnable flags from host variable files.

modules/core/network.nix

@@ -1,10 +1,9 @@
 {
   host,
+  hostId,
   options,
   ...
-}: let
-  inherit (import ../../hosts/${host}/variables.nix) hostId;
-in {
+}: {
   # Defensive assertion for hostname validity (clearer message at eval time)
   assertions = [
     {