fix: YouTubeTranscriptApi.fetch is instance method not class method

The API changed: fetch() requires an instance.
Added: api = YouTubeTranscriptApi() before calling api.fetch()

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

src/tools/youtube.py

@@ -111,7 +111,9 @@ def get_youtube_transcript(video_id: str) -> Dict[str, Any]:
         logger.info(f"Fetching transcript for video: {video_id}")
 
         # Get transcript (auto-detect language, prefer English)
-        transcript_list = YouTubeTranscriptApi.fetch(
+        # Note: fetch() is an instance method in newer versions
+        api = YouTubeTranscriptApi()
+        transcript_list = api.fetch(
             video_id,
             languages=['en', 'en-US', 'en-GB']
         )