feat(player): add explicit detection, inline audio preview, seeking scrubber, and stream endpoint

app/main.py

@@ -79,6 +79,40 @@ async def direct_download(url: str = Query(...)):
         headers={"Content-Disposition": f"attachment; filename*=UTF-8''{encoded_filename}"}
     )
 
+@app.get("/api/stream")
+async def stream_audio(url: str = Query(...)):
+    """Stream audio track for in-browser playback and seeking with HTTP Range support."""
+    provider = sync_manager.get_provider(url)
+    tracks = await provider.resolve(url)
+    if not tracks:
+        raise HTTPException(status_code=404, detail="Track not found")
+    
+    track = tracks[0]
+    dest_path = get_track_dest_path(
+        settings.MUSIC_DIR,
+        artist=track.artist,
+        album=track.album or "Singles",
+        track_num=track.track_number,
+        title=track.title,
+        ext="mp3"
+    )
+
+    if not os.path.exists(dest_path):
+        success = await provider.download_track(track, dest_path)
+        if not success and track.service == "yandex":
+            success = await sync_manager.universal_provider.download_track(track, dest_path)
+        if not success:
+            raise HTTPException(status_code=500, detail="Failed to fetch track audio")
+
+    return FileResponse(
+        dest_path,
+        media_type="audio/mpeg",
+        headers={
+            "Accept-Ranges": "bytes",
+            "Content-Disposition": "inline"
+        }
+    )
+
 @app.post("/api/sync/yandex-likes")
 async def sync_yandex_likes():
     if not settings.YANDEX_MUSIC_TOKEN: