refactor: full codebase cleanup, dependency updates, and lint fixes

Phase 0: Remove ~920 lines of dead code (ThemeBentoPicker, PromoDiscountBadge,
AdminLayout, SettingsSidebar, MovingGradient, EmptyState, miniapp API, unused
types/functions/transitions/skeleton helpers). Fix API barrel file (add 20 missing exports).

Phase 1: Add ErrorBoundary (app/page/widget levels), centralize constants,
add axios timeout, fix staleTime:0 in React Query.

Phase 2: Consolidate hexToHsl, extract email validation, fix duplicate code.

Phase 3: Fix auth race condition (await checkAdminStatus), memoize useCurrency,
add WebSocket message validation.

Phase 4: Extract useBranding, useFeatureFlags, useScrollRestoration from AppShell.

Phase 5: Remove all eslint-disable react-hooks/exhaustive-deps (14 total),
simplify logger, remove deprecated hooks (useBackButton, useTelegramDnd,
useTelegramWebApp).

Dependencies: React 19, react-router 7, zustand 5, i18next 25, react-i18next 16,
eslint-plugin-react-refresh 0.5. Remove unused @lottiefiles/dotlottie-react.
Convert vite manualChunks to function-based approach for react-router v7 compat.

Lint: Fix logger.ts no-unused-expressions, fix react-refresh/only-export-components
in 6 Radix primitive files (const re-exports → direct re-exports), fix
WebSocketProvider exhaustive-deps. Result: 0 errors, 0 warnings.

Add CLAUDE.md to .gitignore.

src/main.tsx

@@ -20,6 +20,7 @@ import {
   isFullscreen,
 } from '@telegram-apps/sdk-react';
 import { AppWithNavigator } from './AppWithNavigator';
+import { ErrorBoundary } from './components/ErrorBoundary';
 import { initLogoPreload } from './api/branding';
 import { getCachedFullscreenEnabled, isTelegramMobile } from './hooks/useTelegramSDK';
 import './i18n';
@@ -100,8 +101,10 @@ const queryClient = new QueryClient({
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
-    <QueryClientProvider client={queryClient}>
-      <AppWithNavigator />
-    </QueryClientProvider>
+    <ErrorBoundary level="app">
+      <QueryClientProvider client={queryClient}>
+        <AppWithNavigator />
+      </QueryClientProvider>
+    </ErrorBoundary>
   </React.StrictMode>,
 );