v0.2.24

Streaming LLM translation, refreshed benchmarks and loud failures.

## Added
- AlignAtt translation backend (`--translation-backend alignatt`): streaming LLM translation through an [Alignatt4LLM](https://github.com/QuentinFuxa/Alignatt4LLM) sidecar. The model drafts ahead over the unstable ASR tail and commits only target words whose attention lands on committed source words, so translations are append-only and released the instant the ASR commits. See [docs/translation-alignatt.md](https://github.com/QuentinFuxa/WhisperLiveKit/blob/main/docs/translation-alignatt.md).
- Benchmark figures re-measured on an H100 with the current backends (the README scatter plots dated from March and misrepresented the qwen3 backends). Raw results in `benchmarks/h100_scatter/`.

## Fixed
- mlx-whisper produced empty captions with torch >= 2.13 (#383, thanks @RobertBartelds-FleetEnergies).
- The server now fails loudly when the ASR backend produces nothing: warmup errors abort startup with the cause, and a watchdog logs an explicit error if audio flows but no text is ever produced.