Phase 4: Translate Shared Components - common, navigation, status labels

- Translate LoadingState and EmptyState components (common namespace)
- Translate Header navigation labels (navigation namespace)
- Translate StatusBadge trade status labels (exchange namespace)
- Create navigation.json translation files for es, en, ca
- Create exchange.json translation files for status/direction/transfer labels
- Update IntlProvider to load navigation and exchange namespaces
- Update frontend tests to expect Spanish translations (default language)
- Configure Playwright to use English language for e2e tests via storageState
- Fix test expectations to match translated strings

All frontend and e2e tests passing.

frontend/e2e/helpers/setup.ts

@@ -0,0 +1,12 @@
+import { Page } from "@playwright/test";
+
+/**
+ * Set language to English for e2e tests.
+ * E2E tests should only test in English according to requirements.
+ * Call this in beforeEach hooks in test files.
+ */
+export async function setEnglishLanguage(page: Page) {
+  await page.addInitScript(() => {
+    window.localStorage.setItem("arbret-locale", "en");
+  });
+}