- TimelineScriptTrack added to the track union; tracks computed emits one
per ScriptTrack in trackOrder, with the show-locked filter honoring its
locked flag
- script track row: drag handle + PhCode name badge + lock button; lane
renders each ScriptFrame as an orange dot with optional action-count
badge
- button instances render inside clip-track lanes as 4 cells labeled
N/H/P/D, colored per state, with a striped pattern on disabled and a
fixed visual width per cell
- new scrub-bar button to add a script track (PhCode icon)
- type narrowing tightened so inGroup checks skip script/group tracks
explicitly rather than relying on the negation
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>