[codex] enable audio compression by default

[kleenkanteen]

Enable audio compression by default

Keep Whispering's "compress audio before transcription" setting enabled by default.

Why:

• It speeds up remote transcription materially. The setting has been about 5x faster for me.
• It is a no-brainer default to leave on, while still letting users opt out in the transcription settings panel.

Impact:

• Fresh installs and resets start with compression enabled.
• The existing checkbox still controls the preference for users who want to turn it off.

---

^{Need help on this PR? Tag /codesmith with what you need. Autofix is disabled.}