feat(themes): declaratively manage icons, cursors, and dark/light modes

- Automatically detect light mode via 'light.mode' file in theme folder
- Read icon theme name from 'icons.theme' file in theme folder
- Switch Stylix polarity and iconTheme based on theme selection
- Add yaru-theme and bibata-cursors to default packages
- Remove obsolete imperative nomarchy-theme-set-gnome script

modules/home/stylix.nix

@@ -21,12 +21,12 @@ in
     image = activeWallpaper;
     base16Scheme = currentPalette;
     
-    # Force dark/light mode based on theme name if possible, or just default to dark
-    polarity = if lib.strings.hasInfix "light" activeThemeName then "light" else "dark";
+    # Use detected light mode state
+    polarity = if config.nomarchy.isLightMode then "light" else "dark";
 
     cursor = {
-      package = pkgs.bibata-cursors;
-      name = "Bibata-Modern-Ice";
+      package = config.nomarchy.cursor.package;
+      name = config.nomarchy.cursor.name;
       size = 24;
     };
 
@@ -65,4 +65,13 @@ in
       gnome.enable = true;
     };
   };
+
+  # GTK Icon Theme configuration
+  gtk = {
+    enable = true;
+    iconTheme = {
+      package = pkgs.yaru-theme;
+      name = config.nomarchy.iconsTheme;
+    };
+  };
 }