Refactor NixOS and Home Manager modules

This makes them more modular and configurable by allowing features to be
enabled per-host.

Squashed commit of the following:

commit e9896d6166125de7aa26ddc63dac3adb196e8c23
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 23:06:23 2024 +0000

    Use mkMerge

    To ensure features isn't overridden and values aren't lost accidentally

commit c9c8ff5d059f08ade3aee9bb4e25bd51d4817a6d
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 22:56:38 2024 +0000

    Move NixOS module imports

commit 4a85bbac9dfa8f06825f6b1fee45ef27befa16d3
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 22:39:54 2024 +0000

    Move Home Manager module imports

commit 6d7a1b0aac68ccc8649fa2d8cd6e8b17ecebb4f0
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 21:15:54 2024 +0000

    Add host-specific Home Manager configurations

commit b32da2fbf7498c9684d8289be0f02800994e9110
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 18:00:00 2024 +0000

    Start to parameterise Home Manager modules

commit e80e89b415849cc4c6051a07b70587ac98724e2c
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 18:00:00 2024 +0000

    Rename wsl commands to home-manager

commit 6d82ed73da3c104fb25117fb843c3f3b5d833180
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 18:00:00 2024 +0000

    Refactor NixOS Home Manager configuration

commit cc5cbf5ac1a407a456d7258dd65a78ba3128a88f
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 08:05:00 2024 +0000

    Refactor WSL Home Manager configuration

commit deaf664a0997871b6f2bb0a8f97d638a91cb10bc
Author: Oliver Davies <oliver@oliverdavies.dev>
Date:   Mon Nov 25 08:04:00 2024 +0000

    Refactor lemp11 configuration

nix/modules/nixos/default.nix

@@ -1,7 +1,16 @@
 {
   imports = [
+    ./autorandr.nix
     ./docker.nix
+    ./fonts.nix
+    ./gitea.nix
+    ./i3.nix
+    ./immich.nix
+    ./jellyfin.nix
     ./kanata.nix
+    ./rofi.nix
     ./rsnapshot.nix
+    ./screenkey.nix
+    ./xbanish.nix
   ];
 }

nix/modules/nixos/desktop/default.nix

@@ -1,14 +0,0 @@
-{
-  imports = [
-    ../.
-    ./autorandr.nix
-    ./fonts.nix
-    ./gitea.nix
-    ./i3.nix
-    ./immich.nix
-    ./jellyfin.nix
-    ./rofi.nix
-    ./screenkey.nix
-    ./xbanish.nix
-  ];
-}

nix/modules/nixos/fonts.nix

@@ -1,7 +1,7 @@
 { pkgs, ... }:
 
 let
-  theme = import ../../../lib/theme { inherit pkgs; };
+  theme = import ../../lib/theme { inherit pkgs; };
 in
 {
   environment.systemPackages = with pkgs; [