examples/play_react_pt.py: accept episode-stem paths. You can now pass .../2026-05-11/episode_005 (no .pt suffix) and the player resolves all matching segments, loads the parent date folder so N/P navigation still works, and seeks to that episode on start.

examples/play_react_pt.py: episode-aware viewer. Accepts a directory of segments — all same-episode segments concatenate into one playback timeline; N/P switches between episodes. Red border + red trail-plot mark on segment-boundary frames. Also supports --save_video_dir for per-episode batch MP4 export.

examples/play_react_pt.py: interactive .pt viewer (same key bindings as twm.visualize, adapted to the downsampled .pt content). Supports both mode1_v1 episodes and mode2_v1 segments. Self-contained (numpy + torch + cv2). Headless MP4 export via --save_video.