Playhead scrub: use constant-pace distance math so ▶ resumes where you dragged

Paul: 'when I move the playhead and hit play it just goes back where it was.' dragPlayhead still computed the measure as (seg+t)*pace (old fixed-bars-per-leg), but goLive's drop-in and the URL now use the distance-based travelForBar

▶ Play it: Food Court Eternity → Smoke Arithmetic → Barometric Stampede — a constellation across three families — the path is the mix https://stellate.app/?genre=vaporwave&seed=8501&path=1679.4415,292.16891,1718.20526&xdur=0.046

3ee93f5 https://github.com/aboard-io/stellate/commit/3ee93f5dd1a0d28d7591fb17dee079c2544459fe