feat(payment): implement first recharge offer functionality and UI updates

src/stores/payment/payment-state.ts

@@ -2,6 +2,7 @@
  * Payment 状态机：State 形状 + 初始值
  */
 import type {
+  FirstRechargeOffer,
   PayChannel,
   PaymentOrderStatus,
   PaymentPlan,
@@ -9,6 +10,8 @@ import type {
 
 export interface PaymentState {
   plans: PaymentPlan[];
+  isFirstRecharge: boolean;
+  firstRechargeOffer: FirstRechargeOffer | null;
   selectedPlanId: string;
   payChannel: PayChannel;
   autoRenew: boolean;
@@ -23,6 +26,8 @@ export interface PaymentState {
 
 export const initialState: PaymentState = {
   plans: [],
+  isFirstRecharge: false,
+  firstRechargeOffer: null,
   selectedPlanId: "",
   payChannel: "stripe",
   autoRenew: true,