add: switch-wallpaper.nix

apps/hyprpaper/switch-wallpaper.nix

@@ -0,0 +1,20 @@
+{ pkgs, ... }:
+
+{
+  environment.systemPackages = with pkgs; [
+    (writeShellScriptBin "switch-wallpaper" ''
+      WALLPAPER=$(${pkgs.zenity}/bin/zenity --file-selection --title="Select Wallpaper" --file-filter="Images | *.jpg *.jpeg *.png *.gif")
+
+      if [ -z "$WALLPAPER" ]; then
+          exit 0
+      fi
+
+      # Preload and set wallpaper using hyprctl (requires hyprpaper running)
+      # We attempt to unload all other wallpapers first to save memory, optionally
+      # ${pkgs.hyprland}/bin/hyprctl hyprpaper unload all
+      
+      ${pkgs.hyprland}/bin/hyprctl hyprpaper preload "$WALLPAPER"
+      ${pkgs.hyprland}/bin/hyprctl hyprpaper wallpaper ",$WALLPAPER"
+    '')
+  ];
+}

modules/home/hyprland.nix

@@ -5,6 +5,7 @@
     ../../apps/walker/home.nix
     # ../../apps/fsel/home.nix
     ../../apps/hyprpaper/home.nix
+    ../../apps/hyprpaper/switch-wallpaper.nix
     ../../apps/tte/home.nix
   ];
 }