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/settings/shell.nix

@@ -0,0 +1,14 @@
+{username, ...}: {
+  programs.noctalia.settings.shell = {
+    app_icon_colorize = true;
+    avatar_path = "/home/${username}/garandos/modules/home/hyprland/face.jpg";
+    corner_radius_scale = 2.0;
+    lang = "pl";
+    launch_apps_as_systemd_services = true;
+    screen_time_enabled = true;
+    time_format = "{:%H:%M:%S}";
+    panel.open_near_click_control_center = true;
+    screen_corners.enabled = true;
+    screenshot.confirm_region = true;
+  };
+}