fix: restore just switch on current nixpkgs

nixos/flake.nix

@@ -228,11 +228,6 @@
         pr = 492656;
         hash = "sha256-0TGZ12iIfSYs6cs5kgWDAyiThJdlLMhqRGUscVQv5hU=";
       }
-      # gws
-      {
-        pr = 496806;
-        hash = "sha256-D5g3B2RigdHXeTybATeJqRssQsgCfGF/5zTg4zQb7+g=";
-      }
       # claude-code
       # {
       #   pr = 464698;

nixos/quickshell.nix

@@ -2,13 +2,19 @@
 makeEnable config "myModules.quickshell" false {
   home-manager.sharedModules = [
     inputs.caelestia-shell.homeManagerModules.default
-    ({ lib, nixos, ... }:
+    ({ lib, nixos, pkgs, ... }:
       let
         hyprlandEnabled = lib.attrByPath ["myModules" "hyprland" "enable"] false nixos.config;
+        system = pkgs.stdenv.hostPlatform.system;
+        caelestiaPackage = inputs.caelestia-shell.packages.${system}.with-cli.override {
+          # Caelestia pins app2unit 1.0.3, which no longer builds on this nixpkgs snapshot.
+          app2unit = pkgs.app2unit;
+        };
       in
       {
         programs.caelestia = {
           enable = true;
+          package = caelestiaPackage;
           cli.enable = true;
           systemd.target = lib.mkDefault (
             if hyprlandEnabled