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/components/ui/BentoCard.tsx

@@ -1,4 +1,4 @@
-import { Link } from 'react-router-dom';
+import { Link } from 'react-router';
 import { forwardRef, useCallback } from 'react';
 import { useHaptic } from '@/platform';
 

src/components/ui/Sheet.tsx

@@ -1,6 +1,5 @@
 import { useEffect, useRef, useCallback, useState, type ReactNode } from 'react';
 import { createPortal } from 'react-dom';
-import { useBackButton } from '@/platform';
 import { useHaptic } from '@/platform';
 
 export interface SheetProps {
@@ -105,9 +104,6 @@ export function Sheet({
 
   const haptic = useHaptic();
 
-  // BackButton integration
-  useBackButton(isOpen ? onClose : null);
-
   // Calculate current height based on snap point
   const currentHeight = `${snapPoints[currentSnapIndex] * 100}vh`;
 

src/components/ui/Skeleton.tsx

@@ -131,69 +131,3 @@ export function Skeleton({
 
   return renderSkeleton(0);
 }
-
-// Convenience components for common use cases
-export function TextSkeleton({
-  lines = 1,
-  className = '',
-  lastLineWidth = '60%',
-}: {
-  lines?: number;
-  className?: string;
-  lastLineWidth?: string;
-}) {
-  return (
-    <div className={`space-y-2 ${className}`}>
-      {Array.from({ length: lines }).map((_, i) => (
-        <Skeleton key={i} variant="text" width={i === lines - 1 ? lastLineWidth : '100%'} />
-      ))}
-    </div>
-  );
-}
-
-export function AvatarSkeleton({
-  size = 40,
-  className = '',
-}: {
-  size?: number;
-  className?: string;
-}) {
-  return <Skeleton variant="avatar" width={size} height={size} className={className} />;
-}
-
-export function CardSkeleton({
-  count = 1,
-  className = '',
-}: {
-  count?: number;
-  className?: string;
-}) {
-  return <Skeleton variant="card" count={count} className={className} />;
-}
-
-export function ListSkeleton({
-  count = 3,
-  className = '',
-}: {
-  count?: number;
-  className?: string;
-}) {
-  return (
-    <div className={`space-y-2 ${className}`}>
-      <Skeleton variant="list" count={count} />
-    </div>
-  );
-}
-
-export function BentoSkeleton({
-  count = 1,
-  className = '',
-}: {
-  count?: number;
-  className?: string;
-}) {
-  return <Skeleton variant="bento" count={count} className={className} />;
-}
-
-// Default export for backwards compatibility
-export default BentoSkeleton;