Update README.md

clean up a graph

README.md

@@ -10,8 +10,8 @@ mux delayed audio → verify A/B.
 ```
 file_a ─┐
         ├─► extract.py ─► extracted/{stem}_{video,audio,proxy} ─► sync_audio_test.py (AST) ─┐
-file_b ─┘                                                                                  ├─► lag (seconds) ─► apply_sync.py ─► output/{stem}_synced.mkv ─► verify_sync.py
-                                                                                  sync_video_test.py (VST) ─┘
+file_b ─┘                                                                                   ├─► lag (seconds) ─► apply_sync.py ─► output/{stem}_synced.mkv ─► verify_sync.py
+                                                                  sync_video_test.py (VST) ─┘
 ```
 
 Lag convention (used everywhere, feeds `apply_sync --lag` directly):