Cross-spec interop validation between ietf-act and ietf-ect:
- new packages/interop/ sibling package (ietf-act-ect-interop)
- 32 tests pass: shared claims, algorithm matrix, DAG structure,
divergence handling, anti-goals
- documents ES256 raw signature wire-compatibility
- documents airtight typ separation (act+jwt vs exec+jwt)
Hazards surfaced:
- ACTLedger.append() silently accepts ECT Payload via duck-typing
(both have .jti) — documented in interop README as a production
hazard requiring external isinstance checks
Session handoff:
- SESSION-2026-04-12.md — snapshot of decisions, artifacts, open
actions, and next-session starting points
Also: session-end commit of hash-format fix propagation to
packages/ect/ (the fix was applied to the old refimpl location
but did not propagate through the parallel package-move agent).
