chore: update voice-to-text dependencies to latest versions

[wilcorrea]

Context

During PR #2 review, CodeRabbit flagged several outdated dependencies in the voice-to-text feature. These were deferred to avoid scope creep and ensure thorough testing.

Dependencies to Update

High Priority (breaking changes)

• rubato 0.16 → 1.0
  • ⚠️ Complete API redesign - requires refactoring in whisper/audio.rs
  • Impact: Audio resampling logic
  • Docs: https://docs.rs/rubato/latest/rubato/

Medium Priority (minor bumps)

• cpal 0.15 → 0.17

  • Impact: Audio device enumeration and capture
  • May require changes in whisper/audio.rs
  • Docs: https://docs.rs/cpal/latest/cpal/

• whisper-rs 0.14 → 0.15

  • Impact: Transcription API
  • Check whisper/transcriber.rs for compatibility
  • Docs: https://docs.rs/whisper-rs/latest/whisper_rs/

Low Priority (patch bumps)

• reqwest 0.12 → 0.13
  • Impact: Model downloads in whisper/model_manager.rs
  • Likely backward compatible

Testing Checklist

After updating each dependency:

• cargo check passes
• Audio recording works on macOS
• Audio recording works on Linux (if applicable)
• Whisper transcription produces correct output
• Model download/management still works
• No memory leaks during long recordings
• Resampling quality unchanged

References

• Original PR: feat: add offline voice-to-text with Whisper and UI improvements #2
• CodeRabbit comment: feat: add offline voice-to-text with Whisper and UI improvements #2 (comment)

Notes

Start with reqwest and whisper-rs (safest), then cpal, and finally rubato (most complex).

Consider creating a dedicated branch chore/update-whisper-deps for this work.

[wilcorrea]

🚨 Urgent: macOS ARM Build Failure

The v0.4.0 release build failed for macOS ARM due to a compilation error in whisper-rs-sys v0.13.1:

error: always_inline function 'vmmlaq_s32' requires target feature 'i8mm', 
but would be inlined into function 'ggml_vec_dot_q4_0_q8_0' that is 
compiled without support for 'i8mm'

Current Status:

• ✅ Linux (AppImage + .deb) - Built successfully
• ✅ Windows (.exe) - Built successfully
• ✅ macOS Intel (.dmg) - Built successfully
• ❌ macOS ARM - Failed to build

Root Cause: whisper-rs 0.14 doesn't compile correctly on GitHub Actions ARM runners due to missing CPU feature flags.

Solution: Updating to whisper-rs 0.15 should fix this (improved ARM support).

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Starting work on this now in branch chore/update-whisper-deps to unblock the release.