e2e attest silently deletes other branches' attestation receipts #1041

What happens

just e2e-attest-python / just e2e-attest-ts (and the other attest recipes) call the local testing-conventions python CLI, currently 0.0.85, which prunes stale receipts as a side effect of e2e attest and auto-commits those deletions alongside the receipt it adds.

Two PRs hit this in a single session on 2026-09-04:

• ci: ratchet typescript one-function-per-file to max_lines = 16 #1039 — the agent noticed, reverted the prune, and amended.
• Split the worker-call progress count by cache hits #1036 — the deletion landed: 28 receipts removed (14 under packages/python/e2e-attestations/, 14 under packages/ts/e2e-attestations/), belonging to unrelated merged branches. Caught in review, restored in 4c0c1c7.

Why CI does not catch it

The e2e-verify gate is diff-based: it asserts only that a branch adds or updates its own receipt. Deleting every other branch's receipt is invisible to it. #1036 was fully green — 65 passing checks — with the deletions in its diff.

Attestation commits on main are add-only, so this is a change in tool behavior, not repo convention.

Why it matters

It will keep happening to every agent that attests locally until something changes. Each occurrence is a silent, unrelated 28-file deletion inside an otherwise-scoped feature PR, and the only thing standing between it and main is a human noticing an attestation entry marked removed in the file list.

Options

1. Pin testing-conventions to a version whose e2e attest is add-only.
2. Stop the just e2e-attest-* recipes from auto-committing — write the receipt, stage nothing, let the author commit it.
3. Add a check asserting no PR deletes a receipt it does not own. Complements the diff-based gate rather than replacing it.

(2) is the smallest and removes the whole class: the tool can prune whatever it likes in the working tree if nothing commits on the author's behalf.

Detecting it on an open PR

gh api repos/thekevinscott/dirsql/pulls/<n>/files --paginate \
  --jq '.[] | select(.filename | test("e2e-attestations")) | "\(.status)\t\(.filename)"'

Every entry should read added.