refactor: remove Rule 3, Story, and Caption processors

- Remove Rule 3 (Scene Chunking) from worker auto-trigger
- Remove rule3_ingest.rs and related imports
- Remove Story/Caption from playground module parsing
- Clean up scan.rs Rule 3 display
- Fix ASRX field name conversion (start_time -> start)

Reason: Story/5W1H/Scene accuracy too poor - will redesign later

scripts/asrx_processor.py

@@ -236,7 +236,16 @@ def process_asrx(video_path: str, output_path: str, uuid: str = "",
             try:
                 with open(asr_path) as f:
                     asr_data = json.load(f)
-                asr_segments = asr_data.get("segments", [])
+                raw_segments = asr_data.get("segments", [])
+                # Convert field names: start_time/end_time -> start/end
+                asr_segments = []
+                for seg in raw_segments:
+                    converted = {
+                        "start": seg.get("start_time", seg.get("start", 0)),
+                        "end": seg.get("end_time", seg.get("end", 0)),
+                        "text": seg.get("text", ""),
+                    }
+                    asr_segments.append(converted)
                 if asr_segments:
                     print(f"[ASRX] Loaded {len(asr_segments)} ASR segments from {asr_path}")
             except Exception as e: