common/display-manager: split file, fix sddm theme, fix default compositor choice

hosts/common/default.nix

@@ -15,6 +15,7 @@ in {
 
     ./services/blueman.nix
     ./services/dbus.nix
+    ./services/display-manager.nix
     ./services/fwupd.nix
     ./services/irqbalance.nix
     ./services/journald.nix

hosts/common/services/display-manager.nix

@@ -0,0 +1,32 @@
+{ config, pkgs, lib, ... }:
+let
+  cfg = config.services.displayManager;
+in
+{
+  services.displayManager = lib.mkIf (!config.machineVars.headless) {
+    enable = true;
+    defaultSession = if config.machineVars.wayland
+                       then "hyprland-uwsm"
+                       else "none+xmonad";
+    sddm = {
+      enable = true;
+      wayland.enable = config.machineVars.wayland;
+      package = pkgs.kdePackages.sddm;
+      theme = "sddm-astronaut-theme";
+      extraPackages = with pkgs.kdePackages; [
+        qt5compat
+        qtmultimedia
+        # pkgs.sddm-astronaut
+      ];
+    };
+  };
+
+  environment.systemPackages = lib.mkIf (cfg.enable && cfg.sddm.enable) [
+    (pkgs.sddm-astronaut.override {
+      themeConfig = {
+        PartialBlur = false;
+        # Background = "Backgrounds/";
+      };
+    })
+  ];
+}

hosts/common/services/xserver.nix

@@ -1,29 +1,5 @@
 { config, pkgs, lib, ... }:
 {
-  services.displayManager = lib.mkIf (!config.machineVars.headless) {
-    enable = true;
-    defaultSession = "none+xmonad";
-    sddm = {
-      enable = true;
-      wayland.enable = config.machineVars.wayland;
-      package = pkgs.kdePackages.sddm;
-      theme = "sddm-astronaut-theme";
-      extraPackages = [
-        pkgs.kdePackages.qt5compat
-        # pkgs.sddm-astronaut
-      ];
-    };
-  };
-
-  environment.systemPackages = [
-    (pkgs.sddm-astronaut.override {
-      themeConfig = {
-        PartialBlur = false;
-        # Background = "Backgrounds/";
-      };
-    })
-  ];
-
   services.xserver = lib.mkIf (!config.machineVars.headless) {
     enable = true;