feat(landing-stats): rebuild charts on shared components + add funnel & breakdowns

The landing stats page rendered raw recharts by hand plus a bespoke progress-bar
list, looking nothing like the Sales/Remnawave stats. Rebuild it on the shared
chart components and add the visualizations the data warrants:

- Daily: MultiSeriesAreaChart (created/paid) + SimpleAreaChart (revenue),
  replacing the hand-rolled area chart and the custom progress-bar list.
- Tariff & traffic sources: BreakdownList; payment methods & gift composition:
  DonutChart — all the same components Sales stats uses.
- New conversion Funnel (created → paid) and a Gift activation card
  (claimed/sent + rate), backed by the new backend breakdowns.
- Containers use the bento-card surface; i18n added in ru/en/zh/fa.

src/api/landings.ts

@@ -326,10 +326,22 @@ export interface LandingTariffStat {
   revenue_kopeks: number;
 }
 
+export interface LandingPaymentMethodStat {
+  method: string;
+  purchases: number;
+  revenue_kopeks: number;
+}
+
+export interface LandingSourceStat {
+  source: string;
+  purchases: number;
+}
+
 export interface LandingStatsResponse {
   total_purchases: number;
   total_revenue_kopeks: number;
   total_gifts: number;
+  total_gifts_claimed: number;
   total_regular: number;
   avg_purchase_kopeks: number;
   total_created: number;
@@ -337,6 +349,8 @@ export interface LandingStatsResponse {
   conversion_rate: number;
   daily_stats: LandingDailyStat[];
   tariff_stats: LandingTariffStat[];
+  payment_method_stats: LandingPaymentMethodStat[];
+  source_stats: LandingSourceStat[];
 }
 
 export type PurchaseItemStatus =