Fix: Use nix flake check for hooks, simplify module, remove apps

hosts/vm/default.nix

@@ -29,8 +29,13 @@ in
     (import ../../modules/secrets {
       inherit lib inputs config;
     })
+    ../../modules/git-hooks
   ];
 
+  services.git-hooks = {
+    enable = true;
+  };
+
   home-manager.users.${username} = import ../../home/hosts/vm {
     inherit inputs config pkgs;
   };