areev-bindings

Playbook for the Python (areev-py, PyO3) and Node (areev-js, napi-rs) bindings — the "scalars in, JSON strings out" FFI convention, keeping the two in lockstep with the core API, and the per-language build/test (maturin/pytest, napi/node --test). Use whenever you add or change a binding method, or need to build/test either binding. Critical gotcha: areev-js is a STANDALONE package, not a cargo workspace member, so…