Fix red develop 170a97295af3

The merge lane found `develop` red at `170a97295af3045f4742e0687a19ef033fe3b08f` on its own: no queued PR merges until it is fixed. Failing (tests and gate stages): - `frontend-smoke-playwright-load-isolated` - … and 1 more: read them in the gate log, as untrusted output The whole gate log: artifact `8980` on lane task 9379. 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: tenant-isolation /settings guard now asserts an attached knob row (Task 9349 left a tenant's first category with cards only). Spec 4/4 green locally, quick gate green; PR #6737 queued in the merge lane. Memory: none applied.