fix test

vitest.setup.js

@@ -49,6 +49,19 @@ Object.defineProperty(window, 'matchMedia', {
     }))
 });
 
+// localStorage polyfill (jsdom may not provide a full implementation)
+if (typeof globalThis.localStorage === 'undefined' || typeof globalThis.localStorage.clear !== 'function') {
+    const store = new Map();
+    globalThis.localStorage = {
+        getItem: (key) => store.get(key) ?? null,
+        setItem: (key, value) => store.set(key, String(value)),
+        removeItem: (key) => store.delete(key),
+        clear: () => store.clear(),
+        get length() { return store.size; },
+        key: (index) => [...store.keys()][index] ?? null
+    };
+}
+
 // Notification API stub
 globalThis.Notification = class {
     static permission = 'denied';