Two XCTAssertFalse(el.waitForExistence(timeout: 3)) sites in
Milestone2UITests always burned the full 3s on the expected-absent
path. Add assertAbsent(_:dwell:) (0.5s dwell + .exists) and use it at
both sites — same coverage, ~6s back per suite run.
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>