Audio recording does not work on Safari

### Description of the bug:

There are no errors but audio recording doesn't seem to work on Safari. It works fine on Chrome.

### Actual vs expected behavior:

Audio recording should work on all major browsers.

### Any other information you'd like to share?

Safari Version 18.1.1 (20619.2.8.11.12) running on Mac OS Desktop Version 15.1.1 (24B91)

1. Git clone
2. Set Gemini API key in .env
3. npm install
4. npm start
5. Open page in Safari
6. Press the Play button to start streaming.
7. No errors, but the recording level remains at zero

This seems to be a bug in utils.ts / audioContext. I will create a PR.