Rearrange the config structure

modules/homebrew.nix

@@ -29,4 +29,12 @@
       # Additional repositories if needed
     ];
   };
+
+  # nix-homebrew configuration for declarative Homebrew installation
+  nix-homebrew = {
+    enable = true;
+    enableRosetta = true;  # Apple Silicon support
+    user = "yanlin";
+    autoMigrate = true;    # Migrate existing Homebrew if present
+  };
 }