Fix microphone staying open when a recording is superseded before it starts - #1428

Description

getUserMedia() is awaited, so a recording can be cancelled, deleted, restarted or unmounted while the permission prompt is still up. When the promise finally resolved, the resulting MediaStream was assigned to a hook that no longer wanted it, or was dropped on the floor entirely — leaving the microphone live and the OS recording indicator on.

Fixes #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).