chore: remove dead overlay entries for non-existent flake inputs

overlays/mods/default.nix

@@ -2,9 +2,6 @@
   # Package modifications
   # This overlay contains package overrides and modifications
 
-  # n8n = import ./n8n.nix {inherit prev;};
-  # beads = import ./beads.nix {inherit prev;};
-
   # Add more modifications here as needed
   # example-package = prev.example-package.override { ... };
 }