fix(sdk): 8 code-review correctness fixes

- setGsapScript: remove element when newScript="" (fixes undo/redo duplicate-script bug)
- parseDeclarations: track quotes so ; inside CSS values (data URIs) doesn't split
- handleRemoveGsapKeyframe: guard against duplicate-percentage ambiguity (return EMPTY)
- resolveKeyframe: return kfs so callers can check uniqueness
- handleSetClassStyle: emit op:"add" (not "replace") when no prior <style> element
- FsAdapter listVersions: Number(f.split("_")[0]) — was NaN due to underscore in key
- FsAdapter doWrite: split try/catch so appendVersion failure doesn't fire error handlers
- FileAdapter playground: add content:"" field to satisfy PersistVersionEntry contract

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

Author: vanceingalls

packages/sdk-playground/src/fileAdapter.ts

@@ -32,7 +32,7 @@ class FileAdapter implements PersistAdapter {
     const res = await fetch("/api/composition/versions");
     if (!res.ok) return [];
     const rows = (await res.json()) as Array<{ key: string; timestamp?: number }>;
-    return rows.map((r) => ({ key: r.key, timestamp: r.timestamp }));
+    return rows.map((r) => ({ key: r.key, content: "", timestamp: r.timestamp }));
   }
 
   async loadFrom(_path: string, versionKey: string): Promise<string | undefined> {

packages/sdk/src/adapters/fs.ts

@@ -44,13 +44,19 @@ class FsAdapter implements PersistAdapter {
   }
 
   private async doWrite(path: string, content: string): Promise<void> {
+    const abs = this.abs(path);
     try {
-      const abs = this.abs(path);
       await mkdir(dirname(abs), { recursive: true });
       await writeFile(abs, content, "utf8");
-      await this.appendVersion(path, content);
     } catch (err) {
       for (const h of this.errorHandlers) h({ error: { message: String(err), cause: err } });
+      return;
+    }
+    // Version archival is best-effort — failure here does not affect the primary write.
+    try {
+      await this.appendVersion(path, content);
+    } catch {
+      // version history unavailable; primary write succeeded
     }
   }
 
@@ -70,7 +76,7 @@ class FsAdapter implements PersistAdapter {
         sorted.map(async (f) => ({
           key: f.replace(/\.html$/, ""),
           content: await readFile(join(dir, f), "utf8"),
-          timestamp: Number(f.replace(/\.html$/, "")),
+          timestamp: Number(f.split("_")[0]),
         })),
       );
     } catch {

packages/sdk/src/engine/cssWriter.ts

@@ -61,9 +61,22 @@ function parseCssRules(css: string): CssRule[] {
 function parseDeclarations(body: string): Record<string, string> {
   const decls: Record<string, string> = {};
   let depth = 0;
+  let quote: string | null = null;
   let start = 0;
   for (let i = 0; i <= body.length; i++) {
     const ch = i < body.length ? body[i]! : ";"; // sentinel flush
+    if (quote) {
+      if (ch === "\\") {
+        i++;
+        continue;
+      } // skip escaped char
+      if (ch === quote) quote = null;
+      continue;
+    }
+    if (ch === '"' || ch === "'") {
+      quote = ch;
+      continue;
+    }
     if (ch === "(") depth++;
     else if (ch === ")") depth--;
     else if (ch === ";" && depth === 0) {

packages/sdk/src/engine/model.ts

@@ -177,7 +177,12 @@ export function getGsapScript(document: Document): string | null {
 }
 
 export function setGsapScript(document: Document, newScript: string): void {
-  let el = findGsapScriptElement(document);
+  const existing = findGsapScriptElement(document);
+  if (!newScript) {
+    existing?.remove();
+    return;
+  }
+  let el = existing;
   if (!el) {
     el = document.createElement("script") as unknown as Element;
     const head =

packages/sdk/src/engine/mutate.ts

@@ -500,7 +500,9 @@ function handleSetClassStyle(
   setStyleSheet(parsed.document, newCss);
   const path = styleSheetPath();
   return {
-    forward: [{ op: "replace", path, value: newCss }],
+    forward: [
+      oldCss === "" ? { op: "add", path, value: newCss } : { op: "replace", path, value: newCss },
+    ],
     inverse: [oldCss === "" ? { op: "remove", path } : { op: "replace", path, value: oldCss }],
   };
 }
@@ -602,7 +604,7 @@ function resolveKeyframe(parsed: ParsedDocument, animationId: string, keyframeIn
   const located = parsedForWrite?.located.find((l) => l.id === animationId);
   const kfs = located?.animation.keyframes?.keyframes;
   if (!kfs || keyframeIndex < 0 || keyframeIndex >= kfs.length) return null;
-  return { script, kf: kfs[keyframeIndex]! };
+  return { script, kf: kfs[keyframeIndex]!, kfs };
 }
 
 // fallow-ignore-next-line complexity
@@ -663,8 +665,11 @@ function handleRemoveGsapKeyframe(
 ): MutationResult {
   const resolved = resolveKeyframe(parsed, animationId, keyframeIndex);
   if (!resolved) return EMPTY;
-  const { script, kf } = resolved;
+  const { script, kf, kfs } = resolved;
   const pct = kf.percentage;
+  // removeKeyframeFromScript matches by percentage; bail if two keyframes share
+  // the same percentage to avoid removing the wrong one.
+  if (kfs.filter((k) => k.percentage === pct).length > 1) return EMPTY;
   const newScript = removeKeyframeFromScript(script, animationId, pct);
   if (newScript === script) return EMPTY;
   setGsapScript(parsed.document, newScript);