[Feature Request] Add true Push-To-Talk voice mode with configurable hotkeys

Bug Description
Allow the voice mode to have true Push-To-Talk with no warmup, delay or cursor jumping with Space (who thought that it's a good idea?). I'm using Wispr Flow only because of that limitation, they allow for easy push to talk feature with Right Ctrl/Right CMD/Right Option keys - single keys and are recording instantly with no delay.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.232
• Feedback ID: 7df2411a-c82a-46a5-914e-9ca5f9f72a47

Errors
The error I got from Opus 5 is not true, because I'm literally using Wispr Flow with Right CMD key binding without an issue even in Terminal.

["Can't be done as literally asked, and I want to flag why before touching anything:

- Terminals don't deliver modifier-only keypresses — a bare Option press sends nothing to Claude Code, so there's no keystroke to bind.
- Terminals also can't distinguish left vs right Option. alt/opt/option are the same key either side (and alt == meta in terminals).

So the nearest thing is Option plus a key. Current binding is voice:pushToTalk → space in the Chat context."]