Resolve all CRITIC audit issues for 0.1.0 release

- Async-safe memo: replace threading.local() explicit stacks with
  contextvars.ContextVar using immutable tuples; add async check_context
- Mixed Scalar bypass: use semantic _is_scalar_token() instead of identity
- Full type-checker parity: pyright, mypy, and ty all pass clean on src/;
  reduce pyright global suppressions from 12 to 6; add mypy/ty to CI
- Move JAX Tree tests to test_jax.py for correct tox env coverage
- Fix docs drift: checker-agnostic language, accurate config sections
- Add beartype tested-range note

Author: acecchini

.github/workflows/ci.yml

@@ -43,6 +43,8 @@ jobs:
       - uses: actions/checkout@v6
       - uses: astral-sh/setup-uv@v7
       - run: uv run pyright src/ tests/typing/
+      - run: uv run mypy src/
+      - run: uv run ty check src/
 
   typecheck-compat:
     runs-on: ubuntu-latest