Read the review card fill from localStorage before picking a new one.

The review screen’s effect ran before draft hydration, so reload always generated a fresh color and overwrote the stored one.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/(app)/create/utils/resolvePreviewSurfaceFallback.ts

@@ -0,0 +1,64 @@
+import type { CreateFlowState } from "../types";
+import {
+  isPreviewSurfaceColor,
+  randomPreviewSurfaceColor,
+} from "../../../../lib/create/previewSurfaceColor";
+import {
+  readAnonymousCreateFlowState,
+  writeAnonymousCreateFlowState,
+} from "./anonymousDraftStorage";
+
+function validPreviewSurfaceColor(
+  value: string | undefined,
+): string | undefined {
+  return typeof value === "string" && isPreviewSurfaceColor(value)
+    ? value
+    : undefined;
+}
+
+/** Existing draft fill from React state or localStorage, if it is a stored hsl. */
+export function readDraftPreviewSurfaceColor(
+  storedFallback?: string,
+): string | undefined {
+  return (
+    validPreviewSurfaceColor(storedFallback) ??
+    validPreviewSurfaceColor(
+      readAnonymousCreateFlowState().previewSurfaceColor,
+    )
+  );
+}
+
+/**
+ * Keep a fallback fill on the anonymous draft immediately. The provider’s
+ * first mirrored write is skipped, so waiting on React state loses the color
+ * across reload. `state` is merged so a write before hydrate does not drop
+ * other draft fields already in memory.
+ */
+export function persistDraftPreviewSurfaceColor(
+  color: string,
+  state: CreateFlowState = {},
+): void {
+  const next = validPreviewSurfaceColor(color);
+  if (!next) return;
+  const current = readAnonymousCreateFlowState();
+  const stored = validPreviewSurfaceColor(current.previewSurfaceColor);
+  writeAnonymousCreateFlowState({
+    ...current,
+    ...state,
+    previewSurfaceColor: stored ?? next,
+  });
+}
+
+/**
+ * Reuse the draft fill when one exists; otherwise pick one and write it now.
+ * Reads localStorage itself so a child effect can run before context hydrates.
+ */
+export function resolvePreviewSurfaceFallback(
+  storedFallback?: string,
+): string {
+  const existing = readDraftPreviewSurfaceColor(storedFallback);
+  if (existing) return existing;
+  const color = randomPreviewSurfaceColor();
+  persistDraftPreviewSurfaceColor(color);
+  return color;
+}