Strengthen the zoom-clamp test to assert z floors at 0.25 in the URL (was a
'does not throw' smoke test) and move the affordance localStorage reset to a
beforeEach so the e2e tests are order-independent (QA review).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
VISUAL-gated screenshots of the first-load affordance + control cluster at
each width and the bottom-sheet-open state at 414px, plus always-on structural
assertions. New snapshots; the #361 desktop baselines are untouched. Baselines
regenerate in CI via --update-snapshots.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>