fix(kon): resolve ort version conflict — stub VAD, fix audio crate

- VAD stubbed: voice_activity_detector and silero-vad-rust both pin ort rc.10
  which conflicts with transcribe-rs requiring ort rc.12. Stubbed until ort
  ecosystem aligns at 2.0.0 stable. All audio treated as speech (matches v0.2).
- Refreshed Cargo.lock to resolve ort rc.12 + whisper-rs 0.16 correctly
- clippy clean

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/audio/Cargo.toml

@@ -10,8 +10,9 @@ kon-core = { path = "../core" }
 # Microphone capture
 cpal = "0.17"
 
-# Voice activity detection (Silero VAD V5)
-voice_activity_detector = "0.2"
+# Voice activity detection — deferred until ort version conflict between
+# VAD crates (ort rc.10) and transcribe-rs (ort rc.12) is resolved upstream.
+# silero-vad-rust = { version = "6", default-features = false }
 
 # High-quality resampling (sinc interpolation)
 rubato = "0.15"