fix(studio): resolve keyframe fallbacks against the clicked element

Three review follow-ups on the editor-callback consolidation.

The keyframe-target resolve now takes the clicked element's key and reads
that element's keyframe cache. The diamond context menu and move-to-playhead
pass no explicit target, so they fell through to the cache of whatever
element happened to be selected: opening the menu on a non-selected
element's diamond resolved against the wrong keyframes.

PropertyPanelFlat opens the Motion group by adjusting state during render
instead of in an effect, so the AnimationCard mounts on the same commit the
focus request arrives on rather than a frame later.

Both animation sections pass a module-level focus consumer instead of a
fresh inline arrow, so AnimationCard's focus effect stops re-running on
every parent render.

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

@@ -6,6 +6,7 @@ import { AnimationCard } from "./AnimationCard";
 import {
   type GsapAnimationEditCallbacks,
   withTrackedGsapAnimationCallbacks,
+  clearFocusedEaseSegment,
 } from "./gsapAnimationCallbacks";
 import { useTrackDesignInput } from "../../contexts/DesignPanelInputContext";
 import { usePlayerStore } from "../../player";
@@ -29,7 +30,6 @@ export const GsapAnimationSection = memo(function GsapAnimationSection({
   const [addMenuOpen, setAddMenuOpen] = useState(false);
   const trackedCallbacks = withTrackedGsapAnimationCallbacks(callbacks, track);
   const focusedEaseSegment = usePlayerStore((s) => s.focusedEaseSegment);
-  const setFocusedEaseSegment = usePlayerStore((s) => s.setFocusedEaseSegment);
 
   return (
     <Section title="Animation" icon={<Film size={15} />}>
@@ -57,7 +57,7 @@ export const GsapAnimationSection = memo(function GsapAnimationSection({
               focusedSegment={
                 focusedEaseSegment?.animationId === anim.id ? focusedEaseSegment : null
               }
-              onFocusSegmentConsumed={() => setFocusedEaseSegment(null)}
+              onFocusSegmentConsumed={clearFocusedEaseSegment}
             />
           ))}