Every state-mutating D-Chain tx now carries a signature + per-account nonce,
verified in consensus before any ledger mutation: recovered signer must equal
the asserted 16-byte user, and the digest binds tx type + nonce + full body
(so the withdraw ref and cancel orderId are signed). secp256k1 + ML-DSA-65,
fail-closed. Previously any caller of the venue RPC could move anyone's funds.
Conservation, identity-width, and ownership invariants preserved; the
signed-order primitive that existed without a caller is now the auth boundary.
Tests across ingest/read/zapingest/e2e adapted to sign; no checks weakened.
zeekay
b30f276a90