axiom-pyo3-interop

Production-grade Python ↔ Rust interop via PyO3 — the FFI-boundary discipline, not single-crate Rust nor pure-Python work. v0.1 ships router + 13 sheets, 3 commands, 1 agent. Covers PyO3 fundamentals (`Bound<'py, T>`, GIL tokens, `#[pymodule]` / `#[pyclass]`), abi3 vs native and the wheel matrix, maturin inside a Cargo workspace, GIL release patterns, batched FFI to amortise crossing cost, zero-copy NumPy via the buffer protocol, Gymnasium environments backed by Rust, error mapping with traceback fidelity, lifecycle and teardown at interpreter shutdown, async across the boundary (`pyo3-async-runtimes`, tokio + asyncio), packaging and wheels (cibuildwheel, abi3, manylinux), debugging boundary panics / segfaults / GIL deadlocks, and the cost-of-crossing performance model. Commands: /scaffold-pyo3-crate, /profile-ffi-boundary, /audit-gil-discipline. Agent: pyo3-reviewer (SME Agent Protocol; sweeps all 13 sheets + 13 boundary anti-patterns). Sibling to `axiom-rust-engineering` (single-crate Rust) and `axiom-rust-workspaces` (multi-crate Rust); composes with both.