v1.6.0

**Chatterbox TTS**
- **New TTS Engine** - Integrated Chatterbox TTS (MIT license) for voice cloning with a single reference sample
- **23 Languages** - English uses the fast default model; other languages auto-switch to the Multilingual model
- **Voice Clone Support** - Added Chatterbox as a Voice Clone engine with exaggeration, CFG weight, temperature, repetition penalty, and top-p controls
- **Conversation Support** - Chatterbox available as a Conversation engine with up to 8 speakers, sequential per-line generation, and configurable pauses

**Voice Changer**
- **New Voice Changer Tool** - Convert any audio to match a target voice using Chatterbox voice conversion
- **Target Voice Selector** - Browse and preview voice samples from your samples folder
- **Source Audio Input** - Upload audio files or record directly from microphone
- **Save to Samples** - Save converted audio directly to your samples folder for use with other tools

**Conversation Tool Improvements**
- **Shared Voice Sample Dropdowns** - Consolidated duplicate per-engine dropdowns into a single shared set of 8, reducing UI bloat
- **Smart Speaker Limit** - Rows 5-8 automatically hidden when using VibeVoice (4 speaker limit)

**Chatterbox Multilingual Fixes**
- **Truncation Fix** - Increased max generation tokens from 1000 to 2048 (~80 seconds max vs ~40 seconds)
- **Premature EOS Fix** - Fixed AlignmentStreamAnalyzer cutting audio short by requiring minimum speech frames before allowing completion
- **macOS Compatibility** - Added MPS/CPU support with proper device mapping and MPS availability checks

**Other Improvements**
- **Python 3.10-3.12 Enforcement** - Setup scripts now auto-discover compatible Python versions and block 3.13+
- **Flash Attention Install** - Added Flash Attention 2 install option to setup-windows.bat
- **Prep Audio Cache Fix** - Delete and clear cache now also remove LuxTTS `.pt` cache files