Optimize Transcription with YouTube Captions, Audio Resampling, and Copy Button

[FabricioMatos]

PR Changes:

• Use youtube captions (auto-captions included) when available to avoid the audio transcription when possible.
• Resample mp3 from 192Khz to 48Kh before the transcription if the audio file is larger than 25MB (current Whisper+Groq limit)
• Add a "Copy" button at the bottom of the page when the summarization is finished to easily copy the content.

[FabricioMatos]

Optimize transcription using YouTube captions when available, 4x audio length support, and Copy button.