Fix flake warnings: modernize outputs, add metadata, clean structure

flake.nix

@@ -66,11 +66,31 @@
       (import ./home/programs/group/flake.nix args)
       (import ./home/programs/nixy/flake.nix args)
       {
+        # Modern app output with metadata
+        apps.${system} = {
+          default = {
+            type = "app";
+            program = "${pkgs.neovim}/bin/nvim";
+            meta = {
+              description = "Improved Vim-based text editor";
+              homepage = "https://neovim.io";
+              license = "Apache-2.0";
+            };
+          };
+        };
+
+        # Formatter output
         formatter.${system} = pkgs.alejandra;
+
+        # Explicit homeManagerModules output (needed for home-manager packages)
+        homeManagerModules = {
+          default = import ./home/programs/group/flake.nix args;
+        };
+
+        # Ensure nixosConfigurations uses modern output format
         nixosConfigurations = {
           thinkpad = import ./hosts/laptop/flake.nix args;
           home-pc = import ./hosts/home-pc/flake.nix args;
-          jack = import ./hosts/server/flake.nix args;
         };
       }
     ];