Create rule flow core infrastructure and routing

app/components/navigation/ConditionalNavigation.tsx

@@ -0,0 +1,24 @@
+"use client";
+
+import { memo } from "react";
+import { usePathname } from "next/navigation";
+import TopNavWithPathname from "./TopNav/TopNavWithPathname";
+
+/**
+ * Conditionally renders TopNav based on pathname.
+ * Hides navigation for /create/* routes (full-screen create flow).
+ */
+const ConditionalNavigation = memo(() => {
+  const pathname = usePathname();
+  const isCreateFlow = pathname?.startsWith("/create");
+
+  if (isCreateFlow) {
+    return null;
+  }
+
+  return <TopNavWithPathname />;
+});
+
+ConditionalNavigation.displayName = "ConditionalNavigation";
+
+export default ConditionalNavigation;