all application options will adapt to environment

when used either with nixos (no home-manager) or home-manager standalone, `features.applications.<name>.enable` options still perform some functionality, rather than assuming a full nixos + home-manager setup like before

modules/components/window-managers/niri.nix

@@ -37,14 +37,12 @@
         ));
       };
 
-      home-manager.sharedModules = [
-        ({ lib, config, ... }: {
-          home.activation.symlinkNiriConfig = lib.hm.dag.entryAfter ["writeBoundary"] (config.helpers.mkSymlinkActivationScript { 
-            target = ".config/niri/config.kdl";
-            source = "dotfiles/${config.info.hostName}/niri.kdl";
-          });
-        })
-      ];
+      home-manager.users.grey = lib.mkIf (config.features.nixos.home-manager.enable) ({ lib, config, ... }: {
+        home.activation.symlinkNiriConfig = lib.hm.dag.entryAfter ["writeBoundary"] (config.helpers.mkSymlinkActivationScript { 
+          target = ".config/niri/config.kdl";
+          source = "dotfiles/${config.info.hostName}/niri.kdl";
+        });
+      });
     };
   };
 }