Best possible solution:

Add the required Matrix changelog entry, let current-head QA-Lab and maintainer handling finish, then land if checks stay green.

Do we have a high-confidence way to reproduce the issue?

Yes, source-level: current main can reject shortened bare-backtick Matrix tool-progress-error previews because that scenario lacks the generic preview-line fallback. I did not run the live Matrix lane locally in this read-only review.

Is this the best way to solve the issue?

Mostly yes: the PR keeps the matcher, approval wait, and retry changes narrow to Matrix/QA behavior, and the earlier prepareTarget contract issue is fixed. The remaining safer path is a small changelog-only repair plus maintainer review before merge.

Full review comments:

• [P3] Add the required changelog entry — extensions/matrix/src/approval-handler.runtime.ts:183
  This PR changes production Matrix approval delivery by retrying direct-room repair and send paths, but it does not touch the root or Matrix changelog. Repo policy requires a one-line user-facing fix entry before merge.
  Confidence: 0.86

Overall correctness: patch is correct
Overall confidence: 0.84

Acceptance criteria:

• git diff --check
• pnpm docs:list

What I checked:

• Current main source-level reproduction: Current main only accepts bullet-style generic Matrix tool-progress preview lines, and the Matrix tool-progress-error scenario does not enable the generic-line fallback, so shortened bare-backtick progress previews can be rejected before the final edit arrives. (extensions/qa-matrix/src/runners/contract/scenario-runtime-room.ts:694, 627b0073f2f7)
• PR implementation direction: The PR head accepts bare-backtick Matrix progress preview lines and enables allowGenericProgressLine for matrix-room-tool-progress-error. (extensions/qa-matrix/src/runners/contract/scenario-runtime-room.ts:694, d74e73f70679)
• Runtime approval retry change: The PR adds retryMatrixApprovalDelivery and routes Matrix approval DM repair and send paths through it, which is production Matrix approval behavior rather than test-only code. (extensions/matrix/src/approval-handler.runtime.ts:183, d74e73f70679)
• Previous review finding fixed: The prepareTarget regression test now includes view: buildExecApprovalView(), satisfying the approval runtime contract called out by the earlier ClawSweeper review. (extensions/matrix/src/approval-handler.runtime.test.ts:388, d74e73f70679)
• Missing changelog: The live PR file list contains no root or Matrix changelog file even though production Matrix approval delivery behavior changes. (d74e73f70679)
• CI and proof state: Latest-head CI, check-test-types, check-docs, CodeQL Critical Quality, and Real behavior proof checks are successful; linked QA-Lab runs at 0345cbc passed Matrix transport/media/e2ee lanes, while current-head manually dispatched QA-Lab follow-up run 25419191833 still has Matrix transport in progress and run 25419191835 is pending. (d74e73f70679)

Likely related people:

• vincentkoc: Recent main-branch commits adjusted Matrix tool-progress matching and target=both approval behavior in the same QA runner/test area this PR changes. (role: recent maintainer; confidence: high; commits: 8e79392dccf4, 36bcf88ffc3a, fcfb6500da10; files: extensions/qa-matrix/src/runners/contract/scenario-runtime-room.ts, extensions/qa-matrix/src/runners/contract/scenario-runtime-approval.ts, extensions/qa-matrix/src/runners/contract/scenarios.test.ts)
• gumadeiras: History shows substantial Matrix QA contract, streaming tool-progress, approval metadata, and native approval lifecycle work that this PR builds on. (role: introduced behavior; confidence: high; commits: 988447ca240c, b9fd13e8d730, ae616777f3b1; files: extensions/qa-matrix/src/runners/contract/scenario-runtime-room.ts, extensions/qa-matrix/src/runners/contract/scenario-runtime-approval.ts, extensions/qa-matrix/src/runners/contract/scenarios.test.ts)
• steipete: Recent history includes Matrix QA profile/runtime work and a bundled Matrix approval-handler refactor near this surface. (role: adjacent maintainer; confidence: medium; commits: 05eda57b3c72, 6987132aed84, 855912b25cb8; files: extensions/matrix/src/approval-handler.runtime.ts, extensions/qa-matrix/src/runners/contract/scenario-runtime-room.ts, extensions/qa-matrix/src/runners/contract/scenarios.test.ts)

Remaining risk / open question:

• The PR has the protected maintainer label, so merge/cleanup still needs explicit maintainer handling.
• The current-head manually dispatched QA-Lab follow-up has not fully completed yet, although completed live proof exists for the pre-rebase head and latest-head CI/proof checks are green.
• A required user-facing changelog entry is missing for the production Matrix approval delivery retry.

Codex review notes: model gpt-5.5, reasoning high; reviewed against 627b0073f2f7.