feat: add blacklisted user blocking screen

Add BlacklistedScreen component, blocking store type, API error interceptor,
and i18n translations (ru, en, zh, fa) for blacklisted users.

src/App.tsx

@@ -4,7 +4,11 @@ import { useAuthStore } from './store/auth';
 import { useBlockingStore } from './store/blocking';
 import Layout from './components/layout/Layout';
 import PageLoader from './components/common/PageLoader';
-import { MaintenanceScreen, ChannelSubscriptionScreen } from './components/blocking';
+import {
+  MaintenanceScreen,
+  ChannelSubscriptionScreen,
+  BlacklistedScreen,
+} from './components/blocking';
 import { saveReturnUrl } from './utils/token';
 import { useAnalyticsCounters } from './hooks/useAnalyticsCounters';
 // Auth pages - load immediately (small)
@@ -122,6 +126,10 @@ function BlockingOverlay() {
     return <ChannelSubscriptionScreen />;
   }
 
+  if (blockingType === 'blacklisted') {
+    return <BlacklistedScreen />;
+  }
+
   return null;
 }