Download buttons now use the already-completed transcription result
instead of re-sending the audio to the server for re-transcription.
This eliminates redundant server work and prevents download failures
when the second transcription attempt errors out.
Also wires up suppressNonSpeech and noSpeechThreshold options
through the API and server pipeline.
Remove references to removed features (image gen, LLM chat, TTS).
Accurately describe current project state as a local whisper.cpp
speech transcription tool with GPU acceleration.