Follow-up cleanup on the catalog-free validation split. Same behavior,
fewer parallel code paths.
- Make the catalog an explicit `Option<&Catalog>` on `pipeline::validate`
instead of a `validate` / `validate_with_catalog` pair, so each call
site states whether catalog rules run.
- Collapse `preprocess_and_validate`, `preprocess_and_validate_structural`,
and `preprocess` into one function that takes `TransformOptions`. Its
`model_resolution` field is now the single source of truth for catalog
awareness, which drops a 12-argument signature and the
`too_many_arguments` allow.
- Replace the duplicated resolve-and-preprocess block in
`operations::validate` with one `validate_in_scope` helper, and drop the
HashSet -> Vec -> HashSet round trip on the catalog path.
- Extract `configured_default_provider`, previously duplicated between
`operations::create` and `operations::validate`.
- Delete `validate_manifest_with_environment_defaults`, which had no
callers outside its own module.
- Share the `server-model.fabro` fixture between the two CLI tests instead
of inlining it twice. The validate test now asserts the rendered output
through the usual snapshot helper, which also removes a hand-rolled
`std::fs::write` and its clippy allow.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
