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/data-display/EmptyState/EmptyState.tsx

@@ -1,56 +0,0 @@
-import { forwardRef, type ReactNode } from 'react';
-import { motion } from 'framer-motion';
-import { cn } from '@/lib/utils';
-import { Button, type ButtonProps } from '@/components/primitives/Button';
-import { fadeIn, fadeInTransition } from '@/components/motion/transitions';
-
-export interface EmptyStateProps {
-  icon?: ReactNode;
-  title: string;
-  description?: string;
-  action?: {
-    label: string;
-    onClick: () => void;
-    variant?: ButtonProps['variant'];
-  };
-  className?: string;
-}
-
-export const EmptyState = forwardRef<HTMLDivElement, EmptyStateProps>(
-  ({ icon, title, description, action, className }, ref) => {
-    return (
-      <motion.div
-        ref={ref}
-        className={cn('flex flex-col items-center justify-center py-12 text-center', className)}
-        variants={fadeIn}
-        initial="initial"
-        animate="animate"
-        transition={fadeInTransition}
-      >
-        {/* Icon */}
-        {icon && (
-          <div className="mb-4 flex h-16 w-16 items-center justify-center rounded-full bg-dark-800/50 text-dark-400">
-            {icon}
-          </div>
-        )}
-
-        {/* Title */}
-        <h3 className="text-lg font-semibold text-dark-100">{title}</h3>
-
-        {/* Description */}
-        {description && <p className="mt-2 max-w-sm text-sm text-dark-400">{description}</p>}
-
-        {/* Action */}
-        {action && (
-          <div className="mt-6">
-            <Button variant={action.variant || 'primary'} onClick={action.onClick}>
-              {action.label}
-            </Button>
-          </div>
-        )}
-      </motion.div>
-    );
-  },
-);
-
-EmptyState.displayName = 'EmptyState';

src/components/data-display/EmptyState/index.ts

@@ -1 +0,0 @@
-export { EmptyState, type EmptyStateProps } from './EmptyState';

src/components/data-display/index.ts

@@ -1,3 +1,2 @@
 export * from './Card';
 export * from './StatCard';
-export * from './EmptyState';