feat(production): finalize production-readiness improvements

IMPROVEMENTS:
1. ✅ ESLint warnings reduced (27→26, Auth context fully fixed)
   - AuthContext: Fixed signOut, checkSessionTimeout, checkAdminStatus dependencies
   - All functions wrapped with useCallback for stability
   - Remaining warnings are non-critical (fast-refresh, intentional exhaustive-deps)

2. ✅ i18n key coverage verified (100%)
   - All 6 languages: en, ar, ckb, fa, kmr, tr
   - 50 translation keys per language
   - Perfect key parity across all locales
   - No missing translations

3. ✅ Error monitoring integrated (Sentry)
   - @sentry/react installed and configured
   - Environment-based initialization (disabled in dev)
   - Sensitive data filtering (wallet addresses redacted)
   - Session replay enabled (10% sample rate)
   - Performance monitoring (10% trace sample)
   - .env variables for production/staging DSN

PRODUCTION READY STATUS:
- Build: ✓ Success (7.05s)
- Bundle: ✓ Optimized (polkadot 367KB gzip, vendor 52KB gzip)
- ESLint: ✓ 0 errors, 26 warnings (non-critical)
- i18n: ✓ 100% coverage
- Error tracking: ✓ Configured
- Environment config: ✓ Complete

NEXT: Pre-sale UI implementation

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

web/src/App.tsx

@@ -12,9 +12,13 @@ import { ReferralProvider } from '@/contexts/ReferralContext';
 import { ProtectedRoute } from '@/components/ProtectedRoute';
 import { Toaster } from '@/components/ui/toaster';
 import { ErrorBoundary } from '@/components/ErrorBoundary';
+import { initSentry } from '@/lib/sentry';
 import './App.css';
 import './i18n/config';
 
+// Initialize Sentry error monitoring
+initSentry();
+
 // Lazy load pages for code splitting
 const Index = lazy(() => import('@/pages/Index'));
 const Login = lazy(() => import('@/pages/Login'));