refactor: compose hosts and home-manager features explicitly

modules/hosts/polaris/default.nix

@@ -5,12 +5,12 @@
 }:
 let
   nixosModules = config.flake.modules.nixos;
+  homeModules = config.flake.modules.homeManager;
   metaLib = config.meta.lib;
 in
 {
   flake.modules.nixos.polaris = metaLib.mkHost {
     name = "polaris";
-    kind = "workstation";
 
     displays = {
       "LG Electronics LG ULTRAGEAR 103NTYT8R290" = {
@@ -33,10 +33,24 @@ in
     };
 
     imports = [
-      nixosModules."workstation-base"
+      nixosModules.workstation-base
       nixosModules.steam
-      nixosModules."user-kiri"
-      nixosModules."user-ergon"
+      (metaLib.mkHostUser {
+        account = metaLib.users.kiri;
+        needsPassword = true;
+        homeImports = [
+          homeModules.kiri-workstation
+          homeModules.noctalia
+        ];
+      })
+      (metaLib.mkHostUser {
+        account = metaLib.users.ergon;
+        needsPassword = true;
+        homeImports = [
+          homeModules.ergon-workstation
+          homeModules.noctalia
+        ];
+      })
       ./_hardware.nix
     ]
     ++ (with inputs.nixos-hardware.nixosModules; [