feat: add admin sales statistics dashboard with 5 analytics tabs

- Add sales stats API client with typed interfaces for all endpoints
- Implement AdminSalesStats page with summary cards and period selector
- Add TrialsTab with provider breakdown donut chart and daily area chart
- Add SalesTab with tariff/period breakdown and daily revenue chart
- Add RenewalsTab with period comparison and trend indicators
- Add AddonsTab with package breakdown bar chart
- Add DepositsTab with payment method breakdown bar chart
- Add SimpleBarChart, SimpleAreaChart, DonutChart components
- Add PeriodSelector with preset periods and custom date range
- Full responsive design (mobile/tablet/desktop/TG Mini App)
- ARIA accessibility (tablist, tab, tabpanel, aria-selected)
- Error handling with isError on all queries
- Empty data guards on all chart components
- i18n support across all 4 locales (en, ru, zh, fa)

src/constants/salesStats.ts

@@ -0,0 +1,39 @@
+import { CHART_COMMON } from './charts';
+
+export const SALES_STATS = {
+  CHART: {
+    ...CHART_COMMON.CHART,
+    HEIGHT: 220,
+    PIE_HEIGHT: 250,
+  },
+  KOPEKS_DIVISOR: CHART_COMMON.KOPEKS_DIVISOR,
+  GRADIENT: CHART_COMMON.GRADIENT,
+  AXIS: {
+    TICK_FONT_SIZE: CHART_COMMON.AXIS.TICK_FONT_SIZE,
+    WIDTH: 40,
+  },
+  TOOLTIP: CHART_COMMON.TOOLTIP,
+  STROKE_WIDTH: CHART_COMMON.STROKE_WIDTH,
+  GRID_DASH: CHART_COMMON.GRID_DASH,
+  STALE_TIME: CHART_COMMON.STALE_TIME,
+  DEFAULT_PERIOD: 30,
+  PERIOD_PRESETS: [7, 30, 90, 0] as const,
+  PROVIDER_COLORS: {
+    telegram: '#229ED9',
+    email: '#34d399',
+    vk: '#4C75A3',
+    yandex: '#FC3F1D',
+    google: '#4285F4',
+    discord: '#5865F2',
+  } as const,
+  BAR_COLORS: [
+    '#34d399',
+    '#818cf8',
+    '#f59e0b',
+    '#ec4899',
+    '#06b6d4',
+    '#8b5cf6',
+    '#f97316',
+    '#14b8a6',
+  ] as const,
+} as const;