Improve page load times and rendering

app/(app)/create/loading.tsx

@@ -0,0 +1,17 @@
+/**
+ * Route-level fallback shown while `/create/...` RSC streams in. Mirrors the
+ * create-flow chrome surface (top bar height + dark canvas) so the user sees
+ * structural feedback instead of a flash of the previous page.
+ */
+export default function CreateFlowRouteLoading() {
+  return (
+    <div
+      className="flex h-screen min-h-0 flex-col overflow-hidden bg-[var(--color-surface-default-primary)]"
+      aria-busy="true"
+      aria-live="polite"
+    >
+      <div className="h-14 w-full border-b border-[var(--color-border-default-primary)] md:h-16" />
+      <div className="flex-1" />
+    </div>
+  );
+}