Split shared host config into dedicated modules

- Add shared modules for boot, hardware, networking, input, and host defaults
- Move host-specific TOML flags to new option namespaces
- Update SSH and service defaults for the new layout

modules/home/desktop/dms/programs/niri.nix

@@ -56,11 +56,11 @@ in {
           layout = "us,ua";
           variant =
             "colemak_dh"
-            + (
-              if osConfig.unexplrd.host.name == "dunamis"
-              then "_ortho"
-              else ""
-            )
+            # + (
+            #   if osConfig.unexplrd.host.name == "dunamis"
+            #   then "_ortho"
+            #   else ""
+            # )
             + ",";
         };
         repeat-delay = 200;