New pure planning layer (services/duration_planner.py) runs after translation,
before TTS: estimates each translated line's natural speech duration (self-
calibrating from the job's already-synthesized segments, static per-language
rates as cold-start fallback) and classifies it fits/tight/impossible against
slot + capped gap borrow, with thresholds derived from fit_planner's own caps
so "impossible" means "would be trimmed". Verdicts ride the /dub/translate
response and badge the segment table; an opt-in (default OFF) LLM pass attaches
one-click shorter-rewrite suggestions for impossible lines. Never blocks
generation — informs before GPU time is burned.
Co-authored-by: mergetest <test@local>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
