feat: multi-track transcription support

SKILL.md:
- Step 2: user can provide multiple track indexes (e.g. mic + Discord)
- Step 4: transcribe each track separately, cross-reference all transcripts
- Step 5: get-transcription supports --track filter

manage_index.py:
- get-transcription: optional --track flag to filter by track index
- Without --track, returns all transcription records (was: latest only)

scripts/index/manage_index.py

@@ -97,7 +97,13 @@ def cmd_add_transcription(args: argparse.Namespace) -> None:
 def cmd_get_transcription(args: argparse.Namespace) -> None:
     video = Path(args.video).expanduser().resolve()
     conn = connect(video)
-    rows = conn.execute("SELECT * FROM transcription ORDER BY created_at DESC").fetchall()
+    if args.track is not None:
+        rows = conn.execute(
+            "SELECT * FROM transcription WHERE track_index = ? ORDER BY created_at DESC",
+            (args.track,),
+        ).fetchall()
+    else:
+        rows = conn.execute("SELECT * FROM transcription ORDER BY created_at DESC").fetchall()
     conn.close()
     if not rows:
         print(json.dumps({"found": False}))
@@ -258,8 +264,9 @@ def main() -> None:
     p_at.add_argument("--duration", type=float, default=None)
 
     # get-transcription
-    p_gt = sub.add_parser("get-transcription", help="Get latest transcription record")
+    p_gt = sub.add_parser("get-transcription", help="Get transcription records (all or by track)")
     p_gt.add_argument("--video", required=True)
+    p_gt.add_argument("--track", type=int, default=None, help="Filter by track index (omit to get all)")
 
     # add-clip
     p_ac = sub.add_parser("add-clip", help="Add a clip record")