Add MultiSeriesAreaChart showing daily deposit amounts per payment
method with human-readable labels and currency formatting. Memoize
all derived data before early returns for React Compiler compat.
Add DualAreaChart to addons tab showing daily traffic purchases vs
device purchases with date-union merge. Add daily_devices field to
AddonsStats type and i18n keys for all 4 locales.
- Add DualAreaChart component for two-series visualization (registrations vs trials)
- Add MultiSeriesAreaChart component for N-series tariff breakdown with dynamic pivoting
- AddonsTab: add device purchases and device revenue stat cards
- SalesTab: add per-tariff daily sales chart using MultiSeriesAreaChart
- TrialsTab: replace single-series area chart with dual-series registrations + trials chart
- Update TypeScript interfaces to match backend schema changes
- Add i18n keys for all new UI elements across en, ru, zh, fa locales
- 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)
