refactor(cabinet): unify all statistics onto the shared StatCard

Bring every stat strip across the admin panel and user cabinet onto the
canonical StatCard (icon chip + label-on-top + tone-coloured value),
matching the sales/Remnawave style the rest of the app already used.

- Convert ~20 hand-rolled stat strips across 21 pages/components
- Remove 4 divergent local StatCard components (Dashboard, Users,
  BanSystem, Payments) and migrate Remnawave's local StatCard (33 cards)
- Extend StatCard with optional subValue, loading skeleton, trailing slot,
  and icon-size normalisation (all backward-compatible)
- StatsGrid nav tiles now use StatCard while keeping link/chevron/loading
- Preserve all data, i18n keys, conditionals and interactive filters;
  fix the dead 'info' colour by mapping it to accent

src/components/admin/userDetail/GiftsTab.tsx

@@ -1,5 +1,6 @@
 import { useTranslation } from 'react-i18next';
-import { SendIcon } from '@/components/icons';
+import { GiftIcon, SendIcon } from '@/components/icons';
+import { StatCard } from '@/components/stats';
 import { useCurrency } from '../../../hooks/useCurrency';
 import type { AdminUserGiftItem, AdminUserGiftsResponse } from '../../../api/adminUsers';
 
@@ -208,18 +209,18 @@ export function GiftsTab({ giftsLoading, giftsData, locale, onNavigateToUser }:
     <div className="space-y-6">
       {/* Summary counters */}
       <div className="grid grid-cols-2 gap-3">
-        <div className="rounded-xl bg-dark-800/50 p-4">
-          <div className="mb-1 text-xs text-dark-500">
-            {t('admin.users.detail.gifts.totalSent')}
-          </div>
-          <div className="text-2xl font-bold text-accent-400">{giftsData.sent_total}</div>
-        </div>
-        <div className="rounded-xl bg-dark-800/50 p-4">
-          <div className="mb-1 text-xs text-dark-500">
-            {t('admin.users.detail.gifts.totalReceived')}
-          </div>
-          <div className="text-2xl font-bold text-success-400">{giftsData.received_total}</div>
-        </div>
+        <StatCard
+          label={t('admin.users.detail.gifts.totalSent')}
+          value={giftsData.sent_total}
+          icon={<GiftIcon className="h-5 w-5" />}
+          tone="accent"
+        />
+        <StatCard
+          label={t('admin.users.detail.gifts.totalReceived')}
+          value={giftsData.received_total}
+          icon={<GiftIcon className="h-5 w-5" />}
+          tone="success"
+        />
       </div>
 
       {/* Sent Gifts */}