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/primitives/DropdownMenu/DropdownMenu.tsx

@@ -5,6 +5,15 @@ import { cn } from '@/lib/utils';
 import { usePlatform } from '@/platform';
 import { dropdown, dropdownTransition } from '../../motion/transitions';
 
+export {
+  Root as DropdownMenu,
+  Trigger as DropdownMenuTrigger,
+  Group as DropdownMenuGroup,
+  Portal as DropdownMenuPortal,
+  Sub as DropdownMenuSub,
+  RadioGroup as DropdownMenuRadioGroup,
+} from '@radix-ui/react-dropdown-menu';
+
 // Icons
 const CheckIcon = () => (
   <svg width="16" height="16" viewBox="0 0 16 16" fill="none">
@@ -36,24 +45,6 @@ const DotIcon = () => (
   </svg>
 );
 
-// Root
-export const DropdownMenu = DropdownMenuPrimitive.Root;
-
-// Trigger
-export const DropdownMenuTrigger = DropdownMenuPrimitive.Trigger;
-
-// Group
-export const DropdownMenuGroup = DropdownMenuPrimitive.Group;
-
-// Portal
-export const DropdownMenuPortal = DropdownMenuPrimitive.Portal;
-
-// Sub
-export const DropdownMenuSub = DropdownMenuPrimitive.Sub;
-
-// RadioGroup
-export const DropdownMenuRadioGroup = DropdownMenuPrimitive.RadioGroup;
-
 // SubTrigger
 export interface DropdownMenuSubTriggerProps extends ComponentPropsWithoutRef<
   typeof DropdownMenuPrimitive.SubTrigger