fix: skip DASH/HLS to bypass YouTube n-challenge requirement

DASH/HLS formats require n-challenge solving (needs JS runtime).
Skipping them falls back to progressive streams which carry audio
and don't need challenge solving.

app/downloader.py

@@ -47,7 +47,7 @@ async def extract_audio(url: str) -> Path:
         "--audio-format", "mp3",
         "--audio-quality", "128K",
         "--format", "bestaudio/best/b",
-        "--extractor-args", "youtube:player_client=tv_embedded,web",
+        "--extractor-args", "youtube:skip=dash,hls",
         "--output", outtmpl,
     ]