fix(sdk): addGsapTween resolves scoped id to bare leaf; validateOp checks target exists

- handleAddGsapTween: strip host prefix for scoped ids (hf-host/hf-leaf →
  selector [data-hf-id="hf-leaf"]) — DOM element carries only the leaf part
- validateOp addGsapTween: call resolveScoped to surface E_TARGET_NOT_FOUND
  before the GSAP script checks (previously can() returned ok for missing targets)
- patches.ts pathToKey: remove dead ?? null (decodePathSegment never returns undefined)

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

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

Author: vanceingalls

packages/sdk/src/engine/mutate.ts

@@ -597,8 +597,11 @@ function handleAddGsapTween(
       ? ((tween.toProperties ?? {}) as Record<string, number | string>)
       : ((tween.toProperties ?? tween.properties ?? {}) as Record<string, number | string>);
 
+  // Scoped ids like "hf-host/hf-leaf" must use the bare leaf id in the GSAP
+  // selector — only the leaf part is written as data-hf-id on the DOM element.
+  const bareTarget = target.includes("/") ? (target.split("/").at(-1) ?? target) : target;
   const animation: Omit<GsapAnimation, "id"> = {
-    targetSelector: `[data-hf-id="${target}"]`,
+    targetSelector: `[data-hf-id="${bareTarget}"]`,
     method: tween.method,
     position: tween.position ?? 0,
     ...(tween.duration !== undefined ? { duration: tween.duration } : {}),
@@ -792,6 +795,12 @@ export function validateOp(parsed: ParsedDocument, op: EditOp): CanResult {
       return CAN_OK;
     case "addGsapTween":
     case "addLabel": {
+      if (op.type === "addGsapTween" && resolveScoped(parsed.document, op.target) === null)
+        return canErr(
+          "E_TARGET_NOT_FOUND",
+          `Element not found: ${op.target}.`,
+          "Verify the id against comp.getElements() or comp.find().",
+        );
       const script = getGsapScript(parsed.document);
       if (!script)
         return canErr(

packages/sdk/src/engine/patches.ts

@@ -118,7 +118,7 @@ export function pathToKey(path: string): string | null {
 
   // /elements/{id} (whole element) → "{id}"
   const elemMatch = /^\/elements\/([^/]+)$/.exec(path);
-  if (elemMatch) return decodePathSegment(elemMatch[1]!) ?? null;
+  if (elemMatch) return decodePathSegment(elemMatch[1]!);
 
   // /variables/{id} → "var.{id}"
   const varMatch = /^\/variables\/(.+)$/.exec(path);