Upgrade CPAL from Kree0 fork to official v0.17.1

[louis030195]

Summary

We're currently using a fork of CPAL (https://github.com/Kree0/cpal.git) for macOS loopback audio capture via ScreenCaptureKit. The official CPAL has now merged loopback support, so we should consider upgrading.

Background

• Current: Using Kree0/cpal fork (created Jul 2024) for ScreenCaptureKit loopback support (PR #894)
• Official CPAL: v0.17.1 (Jan 4, 2025) now has loopback support merged via PR #1003

Why Upgrade

1. Official loopback support merged - PR Fix-transcription-segments-ui #1003 uses Core Audio aggregate devices + taps (different from ScreenCaptureKit approach)
2. Better stability - The ScreenCaptureKit approach in PR [feature] deepgram through screenpipe cloud #894 had issues:
   • Non-deterministic crashes when capturing loopback devices in parallel
   • Crashes on macOS 15 beta
   • Intermittent sound capture issues
3. Active maintenance - Bug fixes, security updates, new features
4. macOS 14.2+ support for loopback

Tasks

• Test official CPAL 0.17.1 loopback on macOS
• Compare audio quality/latency with current fork
• Verify permission handling works correctly
• Update screenpipe-audio/Cargo.toml to use official cpal
• Test on different macOS versions (14.x, 15.x)
• Regression test existing audio capture functionality

References

• CPAL Releases
• PR #894 - ScreenCaptureKit approach (open/superseded)
• PR #1003 - Core Audio loopback (merged)
• Issue #876 - Original loopback request

[louis030195]

Not planned. Closing.