Refactor config to merge modules from platforms

config/login.nix

@@ -0,0 +1,31 @@
+{ config, lib, pkgs, tokyo-night-sddm-src, ... }:
+lib.mkIf (config.custom.platform != "mobile")
+  (let
+    tokyo-night-sddm = with pkgs.libsForQt5; pkgs.stdenv.mkDerivation {
+      name = "tokyo-night-sddm";
+      src = tokyo-night-sddm-src;
+      installPhase = ''
+        cp -f ${./tokyo-night-sddm/theme.conf} ./theme.conf
+        mkdir -p $out/share/sddm/themes/tokyo-night-sddm
+        mv * $out/share/sddm/themes/tokyo-night-sddm
+      '';
+    };
+  in {
+    environment.systemPackages = with pkgs.libsForQt5; [
+      tokyo-night-sddm # Theme
+      qtbase
+      qtsvg
+      qtquickcontrols2
+      qtgraphicaleffects
+    ];
+
+    services.xserver = {
+      enable = true;
+
+      displayManager.defaultSession = "sway";
+      displayManager.sddm = {
+        enable = true;
+        theme = "tokyo-night-sddm";
+      };
+    };
+  })