Enable the `ANN` (flake8-annotations) rule set to require return type
and argument annotations on all function definitions. Pyright strict
already enforces argument types but infers return types silently; this
closes the gap so every function has an explicit return annotation.
Configuration choices:
- `ANN401` (any-type) is ignored: `Any` is sometimes the right answer
and pyright strict already catches genuine misuse.
- `allow-star-arg-any = true`: `*args: Any, **kwargs: Any` is a common
valid pattern for pass-through wrappers.
- Per-file ignores for `test_func_metadata.py` and `test_server.py` where
untyped parameters are intentional (testing schema inference on
unannotated signatures).
- README code snippets (via pytest-examples) exempt — short doc
examples shouldn't need full annotations.
Auto-fix added `-> None` or inferred return types to ~910 functions.
The remaining ~100 were annotated manually — mostly
`@asynccontextmanager` generators, pytest fixtures, and ASGI handlers
that Ruff couldn't infer.
Max Isbey