Fix cutter compare fallback for single-shot matches

scripts/generate_cutter_report.py

@@ -463,9 +463,21 @@ def collect_rows(
 
                 # Frame-locked compare video
                 cmp4 = clips_dir / f"beat_{bid:02d}_compare.mp4"
+                compare_segs = segs
+                if not compare_segs:
+                    seg_dur = max(0.04, min(beat_dur, rec["out_point_s"] - rec["in_point_s"]))
+                    compare_segs = [{
+                        "trailer_offset_s": 0.0,
+                        "duration_s": seg_dur,
+                        "scene_id": rec.get("scene_id"),
+                        "in_point_s": rec["in_point_s"],
+                        "out_point_s": rec["in_point_s"] + seg_dur,
+                        "match_score": rec.get("match_score", 0.0),
+                        "is_confirmed": rec.get("is_confirmed", False),
+                    }]
                 if build_compare_clip(
                     trailer_path, beat["start_s"], beat_dur,
-                    source_path, segs if num_segs >= 1 else [],
+                    source_path, compare_segs,
                     cmp4,
                 ):
                     compare_clip = cmp4