fix: handle YouTube share URLs with si= parameter

- Added ? to regex exclusion set [^&#?]
- Fixes parsing of youtu.be/VIDEO?si=... format
- All URL formats now properly extract video ID

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/routes/commend/youtube_service.py

@@ -95,10 +95,10 @@ def _get_oauth_service():
 def extract_video_id(video_url: str) -> Optional[str]:
     """YouTube URL'sinden video ID'sini çıkarır."""
     patterns = [
-        r"(?<=v=)[^&#]+",
-        r"(?<=be/)[^&#]+",
-        r"(?<=embed/)[^&#]+",
-        r"(?<=shorts/)[^&#]+"
+        r"(?<=v=)[^&#?]+",
+        r"(?<=be/)[^&#?]+",
+        r"(?<=embed/)[^&#?]+",
+        r"(?<=shorts/)[^&#?]+"
     ]
 
     for pattern in patterns: