fix(studio): retime the dragged element's own keyframe

Drag-to-retime resolved the dragged diamond against the selected element's
animations and committed through the selected element's DOM selection, so
dragging a diamond on a non-selected clip retimed the wrong tween. It now
resolves against the clicked element's animations and commits through that
element's selection, matching the delete path.

The three diamond callbacks also take the TimelineKeyframeTarget they already
had instead of five positional fields, and the two copies of the
sourceFile#domId split share splitTimelineElementKey.

packages/studio/src/player/components/timelineCallbacks.ts

@@ -4,6 +4,7 @@ import type { TimelineElement } from "../store/playerStore";
 import type { TimelineMoveOperation } from "../../hooks/timelineMoveAdapter";
 import type { BlockedTimelineEditIntent } from "./timelineEditing";
 import type { PropertyGroupName } from "@hyperframes/core/gsap-parser";
+import type { TimelineKeyframeTarget } from "./timelineKeyframeIdentity";
 
 export interface TimelinePropertyGroupKeyframeToggle {
   animationId: string;
@@ -71,29 +72,16 @@ export interface TimelineEditCallbacks {
   onSplitElement?: (element: TimelineElement, splitTime: number) => Promise<void> | void;
   onRazorSplit?: (element: TimelineElement, splitTime: number) => Promise<void> | void;
   onRazorSplitAll?: (splitTime: number) => Promise<void> | void;
-  onDeleteKeyframe?: (
-    elementId: string,
-    percentage: number,
-    propertyGroup?: string,
-    tweenPercentage?: number,
-    animationId?: string,
-  ) => void;
+  onDeleteKeyframe?: (elementId: string, keyframe: TimelineKeyframeTarget) => void;
   onDeleteAllKeyframes?: (elementId: string) => void;
   onChangeKeyframeEase?: (elementId: string, percentage: number, ease: string) => void;
-  onMoveKeyframeToPlayhead?: (
-    elementId: string,
-    percentage: number,
-    propertyGroup?: string,
-    tweenPercentage?: number,
-    animationId?: string,
-  ) => void;
+  onMoveKeyframeToPlayhead?: (elementId: string, keyframe: TimelineKeyframeTarget) => void;
+  /** Drag-to-retime: `keyframe` identifies the dragged keyframe (its percentage
+   *  is clip-relative), `toClipPercentage` is the neighbour-clamped drop. */
   onMoveKeyframe?: (
     elementId: string,
-    fromClipPercentage: number,
+    keyframe: TimelineKeyframeTarget,
     toClipPercentage: number,
-    propertyGroup?: string,
-    tweenPercentage?: number,
-    animationId?: string,
   ) => Promise<boolean>;
   onToggleKeyframeAtPlayhead?: (element: TimelineElement) => void;
   onTogglePropertyGroupKeyframe?: (