Fix red develop f585b18daab8

The merge lane found `develop` red at `f585b18daab8895b45eed6bf42ac1c516ac1f799` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `tests/project_memory/test_propose_relaxation.py::test_s4_5_repro_is_appended_before_the_body_cut_so_a_long_gotcha_keeps_its_repro` - `tests/project_memory/test_propose_relaxation.py::test_s4_5_a_repro_line_or_fence_already_in_the_body_survives_the_cut_whole` - `api-unit-dc-test` The whole gate log: artifact `13588` on lane task 12168. Make `develop` pass its full gate again. Open a PR as usual: the merge lane merges a PR that fixes some of these and adds no failure even while `develop` is red.

Fixed red develop: Task 12159's B007 rename left _fit_body's last-evidence match None; now taken explicitly. 2 failing tests pass (57/57), quick gate green. PR #7571 queued to merge lane. Memory: none applied.