feat(studio): keyframe system — parser, runtime, timeline UI, design panel, gesture recording (#1311)

* feat(studio): runtime hooks — global time compiler + keyframe runtime

Add the runtime bridge layer: global time compilation (tween % → clip %),
soft reload after mutations, runtime keyframe preview, and keyframe
commit helper.

* feat(studio): runtime hooks — global time compiler + keyframe runtime

Add the runtime bridge layer: global time compilation (tween % → clip %),
soft reload after mutations, runtime keyframe preview, and keyframe
commit helper.

* feat(studio): keyframe cache + commit hooks

Add hooks for keyframe cache population (tween → clip-relative %),
mutation dispatch, keyframe snapping, and audio beat detection.

* feat(studio): timeline UI — dopesheet diamonds + keyboard nav

Add dopesheet strip with diamond keyframe indicators, timeline property
rows, keyboard navigation (J/Shift+J/Delete/K), and feature gate
(STUDIO_KEYFRAMES_ENABLED defaults to false).

* feat(studio): design panel — arc controls + ease curve + stagger

Add arc path controls (curviness slider, auto-rotate), motion path SVG
overlay, ease curve visualization, stagger controls, and expanded
animation card. Includes border-radius editor dependency from #1217.

* feat(studio): gesture recording core

Add gesture recording engine with RAF sampling, modifier key property
mapping (Shift→rotationXY, Alt→rotation, Cmd→opacity),
Ramer-Douglas-Peucker simplification, and ghost trail SVG overlay.

* fix(studio): keyframe drag + recording bug bash

21 fixes: capture GSAP base at drag start, translate:none before
gsap.set, skip reapplyPathOffsets for GSAP elements, clamp recording
seek, _auto flag for 100% keyframes, overlay flash fix, block edits
during recording.

* feat(studio): keyframe integration wiring + docs

Wire App.tsx recording orchestration, TimelineToolbar K/R buttons,
PropertyPanel per-property diamonds, shortcuts panel, toast
notifications, and keyframes guide documentation. All gated on
STUDIO_KEYFRAMES_ENABLED (default false).

packages/studio/src/components/editor/SourceEditor.tsx

@@ -143,7 +143,6 @@ export const SourceEditor = memo(function SourceEditor({
       selection: { anchor: pos },
       effects: EditorView.scrollIntoView(pos, { y: "center" }),
     });
-    view.focus();
   }, [revealOffset]);
 
   return <div ref={mountEditor} className="h-full w-full overflow-hidden" />;