feat: make `cbv` simplifier methods public

This PR makes `mkCbvMethods`, `cbvPre`, and `cbvPost` public so that users can run `cbv` from their own `SimpM` session, e.g. to evaluate several terms with a shared cache or to combine `cbv` with their own simprocs.

`Lean.Meta.Tactic.Cbv.CbvSimproc` becomes a public import of `Lean.Meta.Tactic.Cbv.Main` since `CbvSimprocs` now appears in public signatures.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2 files changed