v0.4.1

Patch Changes

• #66 0c526e0 Thanks @germ-mark! - Fix the agent-handoff binding context so cross-endpoint handoffs validate.

  An agent handoff is signed by the sender against its proposal_context
  (SHA-256 of its recv group's classical id) and validated by the receiver against
  the context that process_incoming stamps on the QueuedRemoteProposal. That
  stamp used the receiver's recv group id — but the two endpoints' recv groups
  are distinct MLS groups (A's recv is B's send), so the values never matched and
  every cross-endpoint handoff signature failed to validate. It stayed latent
  because the only prior consumer never read proposal_context; the first consumer
  that does could not complete its first agent rotation (a Signature-validation
  failure that cascaded to a dropped decrypt).

  Stamp the queued proposal's context from our send group's classical id — the
  reverse channel, which is the sender's recv group — so sign and validate agree.
  Also correct test_proposal_hash_is_digest_of_the_staple_both_sides_agree_on,
  which asserted the receiver's context equalled the receiver's own
  proposal_context (trivially true under the bug); it now asserts equality with
  the sender's, the contract that actually gates handoff validation.