feat(sdk,core): ws-3 — unrollDynamicAnimations acorn port + SDK op (#1501)

* feat(sdk,core): ws-3 — unrollDynamicAnimations acorn port + SDK op

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-authored-by: Miguel Ángel <miguel07alm@protonmail.com>

* test(core): recast-vs-acorn parity + acorn fixes for arc/unroll/keyframe-add/%-removeKeyframe/add-with-keyframes (WS-3.F gate)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat(core): port shiftPositions/scalePositions to acorn writer (WS-3.F)

shiftPositionsInScript + scalePositionsInScript were recast-only GSAP-script
writers reachable from executeGsapMutation (shift-positions/scale-positions),
called by Studio timeline clip move/resize — the last write ops blocking recast
retirement. Ported to gsapWriterAcorn.ts mirroring recast's arithmetic
(shift: max(0,pos+delta); scale: remap pos by duration ratio + scale duration),
reusing a shared overwritePosition helper (also adopted by updateAnimationInScript).
Adds 10 recast-vs-acorn parity tests. Closes the WS-3.F op-coverage gate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Miguel Ángel <miguel07alm@protonmail.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/sdk/src/engine/mutate.ts

@@ -61,6 +61,7 @@ import {
   setArcPathInScript,
   updateArcSegmentInScript,
   removeArcPathFromScript,
+  unrollDynamicAnimations,
 } from "@hyperframes/core/gsap-writer-acorn";
 import { deriveKeyframeBackfillDefaults } from "./keyframeBackfill.js";
 
@@ -208,6 +209,12 @@ function applyArcPathOp(parsed: ParsedDocument, op: EditOp): MutationResult | un
       );
     case "removeArcPath":
       return handleArcPathScript(parsed, s, removeArcPathFromScript(s, op.animationId));
+    case "unrollDynamicAnimations":
+      return handleArcPathScript(
+        parsed,
+        s,
+        unrollDynamicAnimations(s, op.animationId, op.elements),
+      );
     default:
       return undefined;
   }
@@ -1107,6 +1114,7 @@ export function validateOp(parsed: ParsedDocument, op: EditOp): CanResult {
     case "setArcPath":
     case "updateArcSegment":
     case "removeArcPath":
+    case "unrollDynamicAnimations":
     case "deleteAllForSelector":
     case "removeLabel":
       if (getGsapScript(parsed.document) === null)

packages/sdk/src/types.ts

@@ -157,7 +157,16 @@ export type EditOp =
         cp2?: { x: number; y: number };
       };
     }
-  | { type: "removeArcPath"; animationId: string };
+  | { type: "removeArcPath"; animationId: string }
+  | {
+      type: "unrollDynamicAnimations";
+      animationId: string;
+      elements: Array<{
+        selector: string;
+        keyframes: Array<{ percentage: number; properties: Record<string, number | string> }>;
+        easeEach?: string;
+      }>;
+    };
 
 export interface ElasticHold {
   start: number;