[Improved, Fixed] Unblock candidates at the microphone step

Improvements

• The “Allow microphone access” button now shows a spinner and becomes temporarily disabled after a tap, so candidates immediately see that their request is processing instead of wondering if the click registered.
• Start buttons briefly disable after a microphone error to prevent rapid-fire retries that previously caused confusing loops.
• Error and toast messages on the microphone gate are now fully localized in Spanish and French (with English fallback), giving non-English speakers clearer guidance.
• When a browser rejects advanced audio settings, the system automatically retries with a simpler configuration to maximize the chance of connecting.

Fixes

• Resolved an issue that trapped many Spanish-speaking candidates in an endless “mic unavailable” loop, preventing them from starting their AI interview.
• Fixed a bug where tapping “Allow microphone access” appeared to do nothing, leading some users to abandon the interview setup.