Add optional speaker labels and live speaker naming
Bumps submodules:
- caption-local 618f7ff: CPU speaker labels (sherpa-onnx), room cast lists,
/api/rooms/<id>/speakers, capture-page speaker option and shared panel.
- captionninja cb05906: editor speaker naming and Alt+1-9, audience labels,
relay spk field.
- captions-coop-wiki 4386a23: speaker names guide and reference updates.
Compose passes CAPTION_DIARIZATION, CAPTION_SPEAKER_THRESHOLD and
CAPTION_MAX_SPEAKERS through to caption-local; labels are off by default.
trav
466c2d3311