Playhead scrub rewrites the URL measure while stopped

Paul: moving the playhead then hitting play "reverts" and "isn't updating the URL." urlTick fired only from onBar (live) and stopLive — never on a stopped playhead drag, so the address bar's ?m= went stale the moment you scrubbed.

• (The drop-in itself is correct: verified headless that setting startBar=137 and hitting ▶ drops the walk in at serial 137 with matching travel — goLive honors the measure, no revert.

▶ 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=1247&path=1679.4415,292.16891,1718.20526&xdur=0.046

fbb1db5 https://github.com/aboard-io/stellate/commit/fbb1db5f974b0f6456eaf75b1a6cdc3562ef0ca3