feat(sdk,core): ws-3 prerequisites — acorn keyframe-collapse foundation + removeAllKeyframes (#1499)

* feat(sdk,core): ws-3 prerequisites — acorn keyframe-collapse foundation + removeAllKeyframes

P1: gsapWriter.parity.test.ts — recast-vs-acorn parity harness (reparse-equivalence).
P2: move pure keyframe-conversion transforms (resolveConversionProps, cssIdentityValue)
    to recast-free gsapSerialize.ts so the acorn/SDK path can share them.
P3: MagicString splice primitives in gsapWriterAcorn.ts (buildVarsObjectCode, overwriteVarsArg).
P4: reference vertical slice — removeAllKeyframesFromScript ported to acorn writer +
    removeAllKeyframes SDK op (types/mutate/can) + Studio cutover (useGsapKeyframeOps),
    replacing the server-authoritative ponytail stub.

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

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

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

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

* feat(sdk,core): ws-3 — materializeKeyframes + splitIntoPropertyGroups acorn ports + SDK ops

- acorn: buildKeyframeObjectCode, materializeKeyframesFromScript, addAnimationWithKeyframesToScript
- acorn: splitIntoPropertyGroupsFromScript with filterGroupKeyframes/filterGroupProperties helpers
- parity tests: materialize (2 positive + 1 no-op) and split (2 positive + 2 no-op) suites
- SDK types: materializeKeyframes + splitIntoPropertyGroups EditOp variants
- mutate.ts: handlers + can() gates for both new ops
- mutate.gsap.test.ts: 6 new tests (53 total passing)

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

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

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

- acorn: updateAnimationSelectorInScript, insertInheritedStateSetInScript helpers
- acorn: splitAnimationsInScript exported (parity with recast version)
- parity: 4 new fixtures (3 cases + no-op) — 23 total parity tests
- SDK types: splitAnimations EditOp variant
- mutate.ts: handleSplitAnimations + can() gate
- mutate.gsap.test.ts: 3 new tests (56 total passing)

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

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

---------

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

packages/studio/src/hooks/useGsapKeyframeOps.ts

@@ -6,6 +6,8 @@ import { executeOptimistic } from "../utils/optimisticUpdate";
 import {
   sdkGsapKeyframePersist,
   sdkGsapRemoveKeyframePersist,
+  sdkGsapRemoveAllKeyframesPersist,
+  sdkGsapConvertToKeyframesPersist,
   type CutoverDeps,
 } from "../utils/sdkCutover";
 import type { KeyframeCacheEntry } from "../player/store/playerStore";
@@ -191,31 +193,52 @@ export function useGsapKeyframeOps({
   );
 
   const convertToKeyframes = useCallback(
-    (
+    async (
       selection: DomEditSelection,
       animationId: string,
       resolvedFromValues?: Record<string, number | string>,
     ) => {
-      // ponytail: no SDK equivalent; convertToKeyframes stays server-authoritative (T6f scope)
+      if (sdkSession && sdkDeps) {
+        const targetPath = selection.sourceFile || activeCompPath || "index.html";
+        const handled = await sdkGsapConvertToKeyframesPersist(
+          targetPath,
+          animationId,
+          resolvedFromValues,
+          sdkSession,
+          sdkDeps,
+          { label: "Convert to keyframes" },
+        );
+        if (handled) return;
+      }
       return commitMutation(
         selection,
         { type: "convert-to-keyframes", animationId, resolvedFromValues },
         { label: "Convert to keyframes" },
       );
     },
-    [commitMutation],
+    [commitMutation, activeCompPath, sdkSession, sdkDeps],
   );
 
   const removeAllKeyframes = useCallback(
-    (selection: DomEditSelection, animationId: string) => {
-      // ponytail: no SDK equivalent for remove-all-keyframes; stays server-authoritative
+    async (selection: DomEditSelection, animationId: string) => {
+      if (sdkSession && sdkDeps) {
+        const targetPath = selection.sourceFile || activeCompPath || "index.html";
+        const handled = await sdkGsapRemoveAllKeyframesPersist(
+          targetPath,
+          animationId,
+          sdkSession,
+          sdkDeps,
+          { label: "Remove all keyframes" },
+        );
+        if (handled) return;
+      }
       commitMutationSafely(
         selection,
         { type: "remove-all-keyframes", animationId },
         { label: "Remove all keyframes", softReload: true },
       );
     },
-    [commitMutationSafely],
+    [commitMutationSafely, activeCompPath, sdkSession, sdkDeps],
   );
 
   const commitKeyframeAtTime = useCallback(