Mike-Solar
ca64b61156
playback_display_tracks_the_playhead asserted the displayed frame lag the playhead by less than 4 frames at playhead 120 — a render- throughput assumption that fails under machine load (parallel builds) rather than for a broken pipeline, which made the test flaky. It now asserts the machine-speed-independent property: the display advances while the playhead advances (peak displayed grows between the two checkpoints), which still catches a permanently frozen picture.