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/locales/ca/navigation.json

@@ -0,0 +1,11 @@
+{
+  "exchange": "Exchange",
+  "myTrades": "Les Meves Operacions",
+  "myInvites": "Les Meves Invitacions",
+  "myProfile": "El Meu Perfil",
+  "signOut": "Tancar sessió",
+  "trades": "Operacions",
+  "availability": "Disponibilitat",
+  "invites": "Invitacions",
+  "prices": "Preus"
+}