Sentinel decision arc: 17-frame iter42 exact-trace replay. A tracked object closes to min-TTC 0.54s and min-CPA 2.72m; the runtime monitor fires and brakes, then releases. Trace 8c43726c. Use the arrow keys to step through the logged frames, Home and End for the first and last, and space to hand the arc back to playback. With a pointer, scrub the timeline, or hover or tap a tracked object to inspect its persistent id, logged detection score, and real trajectory through the remaining frames.