Add formatSrt/formatVtt/wordsToCues to normalize.ts (the inverse of the
existing parseSrt/parseVtt) and a 'hyperframes transcribe <transcript> --to
srt|vtt' export mode. Word-level whisper transcripts group into cues on
sentence boundaries with maxChars/maxGap guards; imported phrase-level cues
pass through unchanged. Default transcribe behavior is unchanged and no new
dependencies are added.
Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>