Rename noctalia-shell to noctalia and add support

* Rename `nooctalia-plugins` to `noctalia-plugins` in host modules and
  plugin definitions
* Update Hyprland keybindings and exec-once to use the new `noctalia`
  commands
* Add `stylixImage` option and enable pointer cursor in
  `modules/core/user.nix`
* Introduce `modules/home/nixpkgs.nix` to allow unfree packages and
  insecure Electron
* Add full Noctalia configuration module with settings for audio,
  bar, calendar, location, notifications, plugins, shell, wallpaper,
  and widgets
* Enable `noctalia` in `modules/home/stylix.nix` and replace legacy
  `noctalia-shell` imports in `modules/home/default.nix`

modules/home/noctalia/default.nix

@@ -0,0 +1,21 @@
+{
+  inputs,
+  system,
+  ...
+}: {
+  programs.noctalia = {
+    enable = true;
+    package = inputs.noctalia.packages.${system}.default;
+  };
+
+  imports = [
+    ./settings
+  ];
+}
+# {
+#   ...
+# }: {
+#   programs.noctalia.settings = {
+#   };
+# }
+