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/pages/AdminPaymentMethods.tsx

@@ -1,8 +1,7 @@
 import { useState, useCallback, useEffect } from 'react';
-import { useNavigate } from 'react-router-dom';
+import { useNavigate } from 'react-router';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useTranslation } from 'react-i18next';
-import { useBackButton } from '../platform/hooks/useBackButton';
 import { usePlatform } from '../platform/hooks/usePlatform';
 import {
   DndContext,
@@ -11,9 +10,8 @@ import {
   useSensor,
   useSensors,
   type DragEndEvent,
-  type DragStartEvent,
 } from '@dnd-kit/core';
-import { useTelegramDnd } from '../hooks/useTelegramDnd';
+
 import {
   arrayMove,
   SortableContext,
@@ -239,9 +237,6 @@ export default function AdminPaymentMethods() {
   const queryClient = useQueryClient();
   const { capabilities } = usePlatform();
 
-  // Use native Telegram back button in Mini App
-  useBackButton(() => navigate('/admin'));
-
   const [methods, setMethods] = useState<PaymentMethodConfig[]>([]);
   const [orderChanged, setOrderChanged] = useState(false);
   const [toastMessage, setToastMessage] = useState<string | null>(null);
@@ -278,40 +273,18 @@ export default function AdminPaymentMethods() {
     useSensor(KeyboardSensor, { coordinateGetter: sortableKeyboardCoordinates }),
   );
 
-  // Telegram swipe behavior for drag-and-drop
-  const {
-    onDragStart: onTelegramDragStart,
-    onDragEnd: onTelegramDragEnd,
-    onDragCancel: onTelegramDragCancel,
-  } = useTelegramDnd();
-
-  const handleDragStart = useCallback(
-    (_event: DragStartEvent) => {
-      onTelegramDragStart();
-    },
-    [onTelegramDragStart],
-  );
-
-  const handleDragEnd = useCallback(
-    (event: DragEndEvent) => {
-      onTelegramDragEnd();
-      const { active, over } = event;
-      if (over && active.id !== over.id) {
-        setMethods((prev) => {
-          const oldIndex = prev.findIndex((m) => m.method_id === active.id);
-          const newIndex = prev.findIndex((m) => m.method_id === over.id);
-          if (oldIndex === -1 || newIndex === -1) return prev;
-          return arrayMove(prev, oldIndex, newIndex);
-        });
-        setOrderChanged(true);
-      }
-    },
-    [onTelegramDragEnd],
-  );
-
-  const handleDragCancel = useCallback(() => {
-    onTelegramDragCancel();
-  }, [onTelegramDragCancel]);
+  const handleDragEnd = useCallback((event: DragEndEvent) => {
+    const { active, over } = event;
+    if (over && active.id !== over.id) {
+      setMethods((prev) => {
+        const oldIndex = prev.findIndex((m) => m.method_id === active.id);
+        const newIndex = prev.findIndex((m) => m.method_id === over.id);
+        if (oldIndex === -1 || newIndex === -1) return prev;
+        return arrayMove(prev, oldIndex, newIndex);
+      });
+      setOrderChanged(true);
+    }
+  }, []);
 
   const handleSaveOrder = () => {
     saveOrderMutation.mutate(methods.map((m) => m.method_id));
@@ -367,12 +340,7 @@ export default function AdminPaymentMethods() {
             <div className="h-8 w-8 animate-spin rounded-full border-2 border-accent-500 border-t-transparent" />
           </div>
         ) : methods.length > 0 ? (
-          <DndContext
-            sensors={sensors}
-            onDragStart={handleDragStart}
-            onDragEnd={handleDragEnd}
-            onDragCancel={handleDragCancel}
-          >
+          <DndContext sensors={sensors} onDragEnd={handleDragEnd}>
             <SortableContext
               items={methods.map((m) => m.method_id)}
               strategy={verticalListSortingStrategy}