fix(voice): default speech output to Siri

[johnmatthewtennant]

Category: fix
User Impact: New macOS voice conversations now use Siri speech output by default while preserving any voice output the user explicitly selected.

Problem: Berd temporarily defaulted to Pocket TTS on macOS to avoid garbled Siri playback. The Siri audio path has since been normalized, so that workaround no longer reflects the preferred native voice experience.

Solution: Restore Siri as the macOS default while keeping Pocket as the default on other platforms and preserving saved Pocket or Siri selections.

File changes

src/features/voice-conversation/lib/voiceOutputPreference.ts
Selects Siri as the default output backend on macOS and Pocket elsewhere.

src/features/voice-conversation/lib/voiceOutputPreference.test.ts
Updates the macOS default assertions while retaining coverage for non-macOS fallback and explicit saved preferences.

[morgmart]

🤖 Automated code review

Reviewed the exact three-dot comparison e89beaf...1671cd5 with the project code-review and wes-review lenses. The change restores Siri as the macOS default while preserving explicit persisted choices and the non-macOS Pocket fallback. Static inspection found no publishable issues. Supplied GitHub evidence is structurally valid but currently shows no completed check result (combined status pending), so required checks still govern merge readiness. Recommendation: APPROVE.

Deterministic publication result: 0 blocking and 0 non-blocking finding(s) publishable; 0 duplicate(s) suppressed.

Pending checks: 1 check(s) are not complete.

This approval reflects the completed code review only; merge readiness remains governed by the repository's required checks.