fix(ui): inspector now updates on device/frame selection

startDrag set state.selection but didn't render until pointerup's onUp
ran — and onUp can throw on `e.currentTarget.classList.remove` if the
event reference is stale after pointer capture release, which leaves
the inspector stuck on 'Nothing selected.'

One-line fix: call render() right after state.selection assignment so
the inspector + halo update from pointerdown, independent of whether
onUp completes cleanly. The drag-completion render at the end of onUp
stays — when both fire it's idempotent (renders are pure functions of
state).

web/static/main.js

@@ -617,6 +617,11 @@ function startDrag(e, kind, id) {
   if (state.tool) return; // a tool is armed; don't hijack
   e.stopPropagation();
   state.selection = { kind, id };
+  // Render immediately so the inspector reflects the new selection from
+  // pointerdown — independent of whether the drag-completion render at
+  // the end of onUp runs. (Previously, the inspector only updated if
+  // pointerup completed cleanly; any throw in onUp left it stale.)
+  render();
 
   const svg = /** @type {SVGSVGElement} */ ($("#canvas"));
   const start = svgPoint(e);