feat: add recharts analytics to admin campaign stats page

- Move shared chart components (DailyChart, PeriodComparison, StatCard) to src/components/stats/ with configurable label props
- Create shared types for chart data decoupled from partner API
- Add campaign chart data API client with deposits/spending split
- Enhance AdminCampaignStats with daily trends chart, period comparison, top registrations, and deposit/spending stat cards
- Add useChartColors hook with SSR guard and theme-aware CSS variable parsing
- Add cross-platform clipboard utility with execCommand fallback for Telegram WebView
- Add i18n keys for chart analytics across all 4 locales (en, ru, zh, fa)
- Responsive fixes: truncation for long names/values, responsive text sizing, touch-friendly copy buttons

package.json

@@ -50,6 +50,7 @@
     "react-i18next": "^16.5.4",
     "react-router": "^7.13.0",
     "react-twemoji": "^0.7.2",
+    "recharts": "^3.7.0",
     "simplex-noise": "^4.0.3",
     "tailwind-merge": "^3.4.0",
     "zustand": "^5.0.11"