Release v0.20.16

[0.20.16] - 2026-05-04

Bug Fixes

• ci: rustls-everywhere — eliminate openssl-sys from build tree (kills the wheel-build cascade) (e731f87)
• ci: vendored OpenSSL must live in headroom-py, not headroom-proxy (f34f95a)
• ci: wheel before-script must work on Debian aarch64-cross container (1323830)
• PR-F1 classify_auth_mode helper (Phase F kickoff) (fb25a26)
• ci: vendor OpenSSL via cargo + drop x86_64 macOS from wheel matrix (20e482d)
• PR-D2 Bedrock streaming via binary EventStream (32a1fd4)
• PR-D1 native Bedrock InvokeModel route + SigV4 (dd1dadf)
• PR-C5 retire responses_converter.py — Rust owns /v1/responses (76c113d)
• ci: unbreak release pipeline — wheel openssl + dead npm artifact downloads (75fa4a4)
• C4 — /v1/responses streaming + Conversations API in Rust (1352f62)
• C3 — /v1/responses Rust HTTP handler + per-item-type passthrough (70cad6c)
• C2 — /v1/chat/completions Rust handler + OpenAI live-zone (f9b4491)

Refactors

• single-wheel maturin build backend (fixes #355) (aa80ec2)