[audio.cpp] Release 0.7: 62 audio model families (85+ variants), Arena UI for model comparison, MiniMax Music 3, FireRed TTS3/Audio, ControlFoley, Personaplex, and more

audio.cpp 0.7 is out :) This release adds a lot of new audio models and a new way to compare them locally. Audio.cpp is now at 62 model families and 85+ model variants. And it keeps growing! The biggest user-facing change is the new Arena UI. Instead of testing one model at a time, you can now give