Re-flowed storyboard beats starting at 0 and contiguous through DurationSeconds.
Re-timed audio cues mapped to their beat's new position and length.
Total fitted film duration in seconds (equal to the final beat's EndSeconds).
Warnings collected during beat, cue, and film-bound checks.
Narration lines with master-timeline StartSeconds and shifted WordTimings.
Result returned by FitTimelineToNarration.