test_demo_opens_window and test_bare_gate_due_opens_window never mocked
wait_for_display(), so they silently relied on a real, reachable X
display being present. On a dev machine this is always true, so they
passed; on a true headless CI runner (no X server at all) each test
blocked for the real 60s timeout before failing, explaining the CI
run's 131s duration. Mocking it to True (matching the existing
test_gate_due_but_display_not_ready_defers pattern for the False case)
restores hermeticity with no production code change.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A7vbgtFfZmfxJtN5DdtJky
