Whisper's snap_pause_point() finds the nearest sentence boundary
independently per cue, which can move a later cue's pause_point before
an earlier cue's. The renderer then sorts by pause_point, producing
non-sequential cue indices in the timeline.
Add a forward monotonicity pass (clamp each pause_point >= previous) at
three layers for defense-in-depth:
- whisper_service: Phase 3 after consolidation
- video_renderer: before temporal sort in _render_pause_insert_method
- rerender_accessible_video: in _build_placements_with_adjustments
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>