feat: use upstream walker and elephant flakes

modules/capabilities/walker.nix

@@ -1,46 +1,24 @@
+{ inputs, ... }:
 {
   flake.modules.homeManager.walker =
     {
       config,
       lib,
-      pkgs,
       ...
     }:
     let
-      elephantCommand = lib.getExe pkgs.elephant;
-      launcherCommand = lib.getExe config.services.walker.package;
+      launcherCommand = lib.getExe config.programs.walker.package;
     in
     {
-      home.packages = [ pkgs.elephant ];
+      imports = [ inputs.walker.homeManagerModules.default ];
 
-      services.walker = {
+      programs.walker = {
         enable = true;
-        systemd.enable = true;
-      };
-
-      systemd.user.services = {
-        elephant = {
-          Unit = {
-            Description = "Elephant application launcher backend";
-            PartOf = [ "graphical-session.target" ];
-            After = [ "graphical-session.target" ];
-          };
-          Install.WantedBy = [ "graphical-session.target" ];
-          Service = {
-            ExecStart = elephantCommand;
-            Restart = "always";
-            RestartSec = 10;
-          };
-        };
-
-        walker.Unit = {
-          Wants = [ "elephant.service" ];
-          After = [ "elephant.service" ];
-        };
+        runAsService = true;
       };
 
       meta.desktop.launcher = {
-        package = config.services.walker.package;
+        package = config.programs.walker.package;
         commands = {
           open = [ launcherCommand ];
           files = [