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/en/exchange.json

@@ -0,0 +1,17 @@
+{
+  "status": {
+    "pending": "Pending",
+    "completed": "Completed",
+    "userCancelled": "User Cancelled",
+    "adminCancelled": "Admin Cancelled",
+    "noShow": "No Show"
+  },
+  "direction": {
+    "buy": "BUY BTC",
+    "sell": "SELL BTC"
+  },
+  "transferMethod": {
+    "onchain": "Onchain",
+    "lightning": "Lightning"
+  }
+}

frontend/locales/en/navigation.json

@@ -0,0 +1,11 @@
+{
+  "exchange": "Exchange",
+  "myTrades": "My Trades",
+  "myInvites": "My Invites",
+  "myProfile": "My Profile",
+  "signOut": "Sign out",
+  "trades": "Trades",
+  "availability": "Availability",
+  "invites": "Invites",
+  "prices": "Prices"
+}