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/utils/sdkCutover.ts

@@ -293,6 +293,31 @@ export function sdkGsapDeleteAllForSelectorPersist(
   );
 }
 
+export function sdkGsapRemoveAllKeyframesPersist(
+  targetPath: string,
+  animationId: string,
+  sdkSession: Composition | null | undefined,
+  deps: CutoverDeps,
+  options?: CutoverOptions,
+): Promise<boolean> {
+  return dispatchGsapOpAndPersist(targetPath, sdkSession, deps, options, (s) =>
+    s.dispatch({ type: "removeAllKeyframes", animationId }),
+  );
+}
+
+export function sdkGsapConvertToKeyframesPersist(
+  targetPath: string,
+  animationId: string,
+  resolvedFromValues: Record<string, number | string> | undefined,
+  sdkSession: Composition | null | undefined,
+  deps: CutoverDeps,
+  options?: CutoverOptions,
+): Promise<boolean> {
+  return dispatchGsapOpAndPersist(targetPath, sdkSession, deps, options, (s) =>
+    s.dispatch({ type: "convertToKeyframes", animationId, resolvedFromValues }),
+  );
+}
+
 export async function sdkDeletePersist(
   hfId: string,
   originalContent: string,