register ocaml-claude-skills and ocaml-mal

Fill in dune-project metadata (synopsis, tags, description, depends)
for both packages and regenerate their opam files. ocaml-mal was
allow_empty but does have a real lib; the opam now declares its fmt
and alcotest deps properly.

Also rename the Untracked row suffix from '(not in sources.toml)' to
'(no opam package)' since the underlying check looks at opam-repo
discovery, not sources.toml.