feat(python): gtm phase 2 pyo3 bindings for awp-core

[andyjsbell]

Summary

Implements Step 1 of GTM Phase 2 (planning/gtm-phase-2-agent-prompts.md → "Step 1 — GTM Phase 2: PyO3 Bindings"): a Python extension that wraps awp-core's signing path so attestations produced from Python verify byte-identically in Rust.

• New crate crates/awp-python/ — PyO3 abi3-py39 bindings, distribution name awp-core-py, Python import name awp.
• API surface: AgentIdentity.generate / load_or_create / from_secret_bytes, sign_attestation(dict, identity), verify_attestation(att, pubkey), and full Attestation field accessors.
• Byte-identical signatures pinned via a fixed-seed test vector in crates/awp-core/tests/cross_language_vector.rs and crates/awp-python/tests/cross_language.py. Drift on either side fires both test suites.
• Cross-language round-trip uses a new stdin-driven awp-verify binary (crates/awp-core/src/bin/awp_verify.rs). Python pipes a signed attestation through it for Rust-side verification; the reverse direction asserts byte equality of signing_payload.
• make check extended to build the wheel via maturin develop and run pytest (19 tests pass).
• CI matrix (.github/workflows/python-wheels.yml): builds wheels for macOS (arm64 + x86_64), Linux (x86_64 + aarch64 manylinux 2_28), and Windows (x86_64); runs pytest on Python 3.9 + 3.12 per platform; TestPyPI publish gated by manual workflow_dispatch per the GTM plan.

Test plan

• make check passes (cargo fmt clean, clippy -D warnings clean, cargo test --workspace --exclude awp-python green, maturin develop + pytest 19/19 green).
• Existing Rust examples unaffected (cargo run --example kyc_receipts, cargo run --example dispatcher_flow).
• Spec smoke test: python -c "import awp; ident = awp.AgentIdentity.generate('agent-test'); att = awp.sign_attestation({'task': 'hello'}, ident); assert awp.verify_attestation(att, ident.public_key); print('ok')" → ok.
• Cross-language self-test: python -m pytest crates/awp-python/tests/cross_language.py -v → 7 passed (sign_python_verify_rust, sign_rust_verify_python, canonical_bytes_match, plus 4 more).
• CI matrix produces all 5 platform wheels on PR (will validate on first push).

Non-goals (deferred)

• Real-PyPI publish — gated on Phase 2 design-partner close per the plan.
• Async API, streaming attestations, multi-process coordination.
• LangGraph SDK / awp-cloud integration — handled by parallel Steps 2-3 in the same phase.

Implements Step 1 — PyO3 Bindings.

🤖 Generated with Claude Code

[andyjsbell]

Agent Run Report

Implementation Commits

• 8ab3818 feat(core): add awp-verify binary and cross-language signing vector
• b9e2a8f feat(python): add awp-core-py PyO3 bindings for sign/verify
• f023998 chore(ci): extend make check with awp-python wheel + pytest gate
• 74e3411 feat(ci): add python wheel matrix workflow with TestPyPI publish gate

Review Report

Requirements Checked

• Workspace member crates/awp-python added — PASS
• PyO3 with abi3-py39 feature, Cargo lib name awp_core_py, Python import awp — PASS
• API surface (sign_attestation, verify_attestation, AgentIdentity.load_or_create, AgentIdentity.generate) — PASS
• Attestation field accessors (id, agent_id, agent_pubkey, task_hash, output_hash, output, status, references, timestamp, signature) — PASS
• payload: dict canonicalised inside Rust via py_to_json_value (no pre-serialisation in Python) — PASS
• Byte-identical signing across Rust and Python (pinned signature, signing_payload, output_hash hex on both sides) — PASS
• Cross-language self-test both directions (test_sign_python_verify_rust, test_sign_rust_verify_python) — PASS
• Byte-equality of signing_payload bytes (not just signature verify) — PASS
• Hardcoded expected-signature test vector duplicated and cross-checked Rust/Python — PASS
• maturin-based build with pyproject.toml — PASS
• .github/workflows/python-wheels.yml covering macOS (arm64+x86_64), Linux (x86_64+aarch64 manylinux 2_28), Windows (x86_64); pytest on 3.9 + 3.12 to validate abi3 — PASS
• TestPyPI publish gated by manual workflow_dispatch with publish_testpypi input — PASS
• README.md covers install, usage, byte-identical guarantee (with worked example), FFI boundary, limitations — PASS
• Python tests for identity round-trip + signing round-trip — PASS
• make check extended to run Python tests — PASS
• Rust examples (kyc_receipts, dispatcher_flow) unaffected — PASS (both run unchanged)
• Do Not Touch: no edits to services/awp-cloud/, python/awp-langgraph/, tools/landing-page/ — PASS (paths absent or untouched)
• Attestation::signing_payload in crates/awp-core/src/attestation.rs untouched — PASS (file unchanged in diff)
• crates/awp-core/ changes additive only (new bin + Cargo.toml bin section + cross-language test vector) — PASS
• crates/awp-agents/ untouched — PASS

Gaps Found

None.

Fixes Made

None.

Quality Gate

make check: PASS (cargo fmt clean, clippy -D warnings clean, 62 awp-core unit tests + 6 cross-language vector tests + 19 Python pytest tests all green, maturin develop succeeds, awp-verify binary built).

Reviewer note

The spec phrasing "Module name: awp_core_py (exposed to Python as awp)" is implemented by setting [lib] name = "awp_core_py" in Cargo (so the compiled artifact carries that name) and using module-name = "awp._native" in [tool.maturin] so the Python package directory at crates/awp-python/python/awp/ re-exports the native symbols. User-facing import is import awp, which is the load-bearing surface; the underlying native submodule is named _native rather than literally awp_core_py. The Cargo lib name matches the spec, the Python import name matches the spec — no fix made.