Takes a caption-sized chunk off oversized transcript when possible.
Once past softMax, prefers the last complete sentence that still fits in
that window so continuous speech becomes short caption/TTS units.
Parameters
committed: string
Transcript awaiting a pause / provider final.
softMax: number = STREAMING_UTTERANCE_SOFT_MAX_CHARS
Prefer a break once length reaches this.
hardMax: number = STREAMING_UTTERANCE_HARD_MAX_CHARS
Force a clause/word break at/before this length when needed.
Takes a caption-sized chunk off oversized transcript when possible. Once past
softMax, prefers the last complete sentence that still fits in that window so continuous speech becomes short caption/TTS units.