Separate common xserver options from plasma.nix, add picom and i3 configs

nixos/desktop/i3.nix

@@ -0,0 +1,25 @@
+{ ... }:
+{
+  imports = [
+    ./common.nix
+    ./xserver.nix
+    ./picom.nix
+  ];
+  services.xserver = {
+    desktopManager = {
+      xterm.enable = false;
+      xfce = {
+        enable = true;
+        noDesktop = true;
+        enableXfwm = false;
+      };
+    };
+    displayManager = {
+      defaultSession = "none+i3";
+      lightdm.enable = true;
+    };
+    windowManager.i3 = {
+      enable = true;
+    };
+  };
+}

nixos/desktop/picom.nix

@@ -0,0 +1,22 @@
+{ ... }:
+{
+  imports = [
+    ./common.nix
+  ];
+  services.picom = {
+    enable = true;
+    shadow = true;
+    fade = true;
+    activeOpacity = 1.0;
+    inactiveOpacity = 0.8;
+    settings = {
+      blur =
+        {
+          method = "dual_kawase";
+          size = 10;
+          deviation = 5.0;
+          strength = 7;
+        };
+    };
+  };
+}

nixos/desktop/plasma.nix

@@ -2,6 +2,8 @@
 {
   imports = [
     ./common.nix
+    ./xserver.nix
+    ./picom.nix
   ];
   # Enable the X11 windowing system.
   services.xserver.enable = true;
@@ -16,13 +18,4 @@
     libsForQt5.lightly
     catppuccin-kde
   ];
-
-  # Configure keymap in X11
-  services.xserver = {
-    layout = "gb";
-    xkbVariant = "";
-  };
-
-  # Configure console keymap
-  console.keyMap = "uk";
 }

nixos/desktop/xserver.nix

@@ -0,0 +1,13 @@
+{ ... }:
+{
+  imports = [
+    ./common.nix
+  ];
+  services.xserver = {
+    enable = true;
+    layout = "gb";
+    xkbVariant = "";
+  };
+
+  console.keyMap = "uk";
+}