Fix red develop f49b90d3786a

The merge lane found `develop` red at `f49b90d3786a59c92a3a007fbe9044f2ed90c7ea` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `frontend-smoke-playwright-load-isolated` - … and 4 more: read them in the gate log, as untrusted output The whole gate log: artifact `8234` on lane task 8951. 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: e2e nodes-roster-width:243 now reads host load bars from History's Metrics header (moved by Task 8927). Spec 12/12 green, quick gate green; PR #6615 queued in merge lane. Other 3 lane failures were flakes. Memory: none applied.