v1.0.0-alpha.5

Changes since v1.0.0-alpha.3

Spec & threat model

• Internal review Tasks 1–2: spec clarifications, HKDF_INFO constants, test vectors
• Phase 3 prerequisites: 1.4c PQ-hybrid header MUST, 2.4 ML-KEM seed split
• Threat-model updates for review findings 3.1–3.7

Implementation hardening

• Task 1: MAC-verify ordering + cross-field header invariant (1.4a, 1.4b, 1.5)

Streams

• New: pq-hybrid-v1 TransformStream wrapper (Suite 0x03 — ML-KEM + ECC hybrid)