feat: add global theme mode and Yazi shortcut

- Added theme.mode to config.nix for global dark/light mode control.
- Updated Matugen to apply GTK dark mode preferences based on the global theme.
- Added a Hyprland bind (SUPER+X) to launch Yazi via uwsm.

apps/yazi/default.nix

@@ -71,6 +71,12 @@
     fi
   '';
 in {
+  wayland.windowManager.hyprland.settings = {
+    bindd = [
+      "SUPER, X, Open File Manager, exec, uwsm app -- yazi"
+    ];
+  };
+
   programs.yazi = {
     enable = true;
     enableFishIntegration = true;
@@ -109,7 +115,7 @@ in {
     default=hyprland;gtk
     org.freedesktop.impl.portal.FileChooser=termfilechooser
   '';
-  
+
   xdg.mimeApps = {
     enable = true;
     defaultApplications = {