Fix red develop 42967d300887

The merge lane found `develop` red at `42967d3008874e66adfbfed21ca4df17f9494a7e` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `frontend-smoke-playwright-load-isolated` - … and 3 more: read them in the gate log, as untrusted output The whole gate log: the Artifacts tab of lane task 8206. 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's 3 Playwright failures: FeedList nested-outline ladder bug (Task 7944 inset) plus two specs updated to Task 8028/8142 behaviour. Local smoke 296/0, quick gate green, visual check OK. PR #6349 queued to lane. Draft follow-up #8211.