refactor: create shared react-i18next mock to reduce duplication (#29711)

web/__mocks__/react-i18next.ts

@@ -0,0 +1,34 @@
+/**
+ * Shared mock for react-i18next
+ *
+ * Jest automatically uses this mock when react-i18next is imported in tests.
+ * The default behavior returns the translation key as-is, which is suitable
+ * for most test scenarios.
+ *
+ * For tests that need custom translations, you can override with jest.mock():
+ *
+ * @example
+ * jest.mock('react-i18next', () => ({
+ *   useTranslation: () => ({
+ *     t: (key: string) => {
+ *       if (key === 'some.key') return 'Custom translation'
+ *       return key
+ *     },
+ *   }),
+ * }))
+ */
+
+export const useTranslation = () => ({
+  t: (key: string) => key,
+  i18n: {
+    language: 'en',
+    changeLanguage: jest.fn(),
+  },
+})
+
+export const Trans = ({ children }: { children?: React.ReactNode }) => children
+
+export const initReactI18next = {
+  type: '3rdParty',
+  init: jest.fn(),
+}