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/Sheet/Sheet.tsx

@@ -10,7 +10,6 @@ import {
 } from 'react';
 import { cn } from '@/lib/utils';
 import { usePlatform } from '@/platform';
-import { useBackButton } from '@/platform';
 import {
   backdrop,
   backdropTransition,
@@ -18,6 +17,12 @@ import {
   sheetTransition,
 } from '../../motion/transitions';
 
+export {
+  Trigger as SheetTrigger,
+  Portal as SheetPortal,
+  Close as SheetClose,
+} from '@radix-ui/react-dialog';
+
 // Close icon
 const CloseIcon = () => (
   <svg width="16" height="16" viewBox="0 0 16 16" fill="none">
@@ -79,15 +84,6 @@ export const Sheet = ({ children, open, onOpenChange, onClose, ...props }: Sheet
   );
 };
 
-// Trigger
-export const SheetTrigger = DialogPrimitive.Trigger;
-
-// Portal
-export const SheetPortal = DialogPrimitive.Portal;
-
-// Close
-export const SheetClose = DialogPrimitive.Close;
-
 // Overlay
 export type SheetOverlayProps = ComponentPropsWithoutRef<typeof DialogPrimitive.Overlay>;
 
@@ -138,9 +134,6 @@ export const SheetContent = forwardRef<HTMLDivElement, SheetContentProps>(
     const { open, onClose } = useContext(SheetContext);
     const { haptic } = usePlatform();
     const dragControls = useDragControls();
-    // Back button integration
-    useBackButton(open ? onClose : null);
-
     const handleDragEnd = useCallback(
       (_: MouseEvent | TouchEvent | PointerEvent, info: PanInfo) => {
         const velocity = info.velocity.y;
@@ -157,7 +150,7 @@ export const SheetContent = forwardRef<HTMLDivElement, SheetContentProps>(
     );
 
     return (
-      <SheetPortal forceMount>
+      <DialogPrimitive.Portal forceMount>
         <AnimatePresence mode="wait">
           {open && (
             <>
@@ -221,7 +214,7 @@ export const SheetContent = forwardRef<HTMLDivElement, SheetContentProps>(
             </>
           )}
         </AnimatePresence>
-      </SheetPortal>
+      </DialogPrimitive.Portal>
     );
   },
 );