auto-claude: subtask-1-2 - Create client-side CSRF token retrieval utility

src/lib/csrf/client.ts

@@ -0,0 +1,17 @@
+const CSRF_META_TAG_NAME = 'csrf-token';
+
+/**
+ * Get the CSRF token from the meta tag in the document head
+ * The server should render: <meta name="csrf-token" content="..." />
+ */
+export function getCsrfToken(): string | null {
+  if (typeof document === 'undefined') {
+    return null;
+  }
+
+  const metaTag = document.querySelector<HTMLMetaElement>(
+    `meta[name="${CSRF_META_TAG_NAME}"]`
+  );
+
+  return metaTag?.content || null;
+}