stub async-storage for vitest to fix unhandled window error

vitest.config.ts

@@ -120,6 +120,15 @@ export default defineConfig({
        */
       {find: /^expo$/, replacement: r('./vitest/expo-stub.ts')},
 
+      /*
+       * async-storage references `window` at module load, undefined under
+       * node. Stubbed with an in-memory implementation.
+       */
+      {
+        find: /^@react-native-async-storage\/async-storage$/,
+        replacement: r('./vitest/async-storage-stub.ts'),
+      },
+
       /*
        * Former Jest moduleNameMapper entries. Vite's ESM resolution may make
        * some of these unnecessary, but they're harmless and proven, so keep

vitest/async-storage-stub.ts

@@ -0,0 +1,27 @@
+/*
+ * Stub for @react-native-async-storage/async-storage. The real package
+ * references `window` at module load, which is undefined in Vitest's node
+ * environment. The package ships an official jest mock, but it relies on the
+ * `jest` global, so we provide a small in-memory implementation instead.
+ *
+ * Aliased in place of @react-native-async-storage/async-storage via
+ * resolve.alias in vitest.config.ts. Test-reachable code only uses
+ * getItem/setItem/removeItem.
+ */
+const store = new Map<string, string>()
+
+const AsyncStorage = {
+  getItem(key: string): Promise<string | null> {
+    return Promise.resolve(store.has(key) ? store.get(key)! : null)
+  },
+  setItem(key: string, value: string): Promise<void> {
+    store.set(key, value)
+    return Promise.resolve()
+  },
+  removeItem(key: string): Promise<void> {
+    store.delete(key)
+    return Promise.resolve()
+  },
+}
+
+export default AsyncStorage