feat(payment): add complete payment system with multi-provider support

Add a full payment and subscription system supporting EasyPay (Alipay/WeChat),
Stripe, and direct Alipay/WeChat Pay providers with multi-instance load balancing.

frontend/src/types/index.ts

@@ -106,6 +106,7 @@ export interface PublicSettings {
   hide_ccs_import_button: boolean
   purchase_subscription_enabled: boolean
   purchase_subscription_url: string
+  payment_enabled: boolean
   custom_menu_items: CustomMenuItem[]
   custom_endpoints: CustomEndpoint[]
   linuxdo_oauth_enabled: boolean
@@ -1629,3 +1630,6 @@ export interface UpdateScheduledTestPlanRequest {
   max_results?: number
   auto_recover?: boolean
 }
+
+// Payment types
+export type { SubscriptionPlan, PaymentOrder, CheckoutInfoResponse } from './payment'

frontend/src/types/payment.ts

@@ -0,0 +1,173 @@
+/**
+ * Payment System Type Definitions
+ */
+
+// ==================== Enums / Union Types ====================
+
+export type OrderStatus =
+  | 'PENDING'
+  | 'PAID'
+  | 'RECHARGING'
+  | 'COMPLETED'
+  | 'EXPIRED'
+  | 'CANCELLED'
+  | 'FAILED'
+  | 'REFUND_REQUESTED'
+  | 'REFUNDING'
+  | 'PARTIALLY_REFUNDED'
+  | 'REFUNDED'
+  | 'REFUND_FAILED'
+
+export type PaymentType = 'alipay' | 'wxpay' | 'alipay_direct' | 'wxpay_direct' | 'stripe' | 'easypay'
+
+export type OrderType = 'balance' | 'subscription'
+
+// ==================== Configuration ====================
+
+export interface PaymentConfig {
+  payment_enabled: boolean
+  min_amount: number
+  max_amount: number
+  daily_limit: number
+  max_pending_orders: number
+  order_timeout_minutes: number
+  balance_disabled: boolean
+  enabled_payment_types: PaymentType[]
+  help_image_url: string
+  help_text: string
+  stripe_publishable_key: string
+}
+
+export interface MethodLimit {
+  daily_limit: number
+  daily_used: number
+  daily_remaining: number
+  single_min: number
+  single_max: number
+  fee_rate: number
+  available: boolean
+}
+
+/** Response from /payment/limits API */
+export interface MethodLimitsResponse {
+  methods: Record<string, MethodLimit>
+  global_min: number  // widest min across all methods; 0 = no minimum
+  global_max: number  // widest max across all methods; 0 = no maximum
+}
+
+/** Response from /payment/checkout-info API — single call for the payment page */
+export interface CheckoutInfoResponse {
+  methods: Record<string, MethodLimit>
+  global_min: number
+  global_max: number
+  plans: SubscriptionPlan[]
+  balance_disabled: boolean
+  help_text: string
+  help_image_url: string
+  stripe_publishable_key: string
+}
+
+// ==================== Orders ====================
+
+export interface PaymentOrder {
+  id: number
+  user_id: number
+  amount: number
+  pay_amount: number
+  fee_rate: number
+  payment_type: string
+  out_trade_no: string
+  status: OrderStatus
+  order_type: OrderType
+  created_at: string
+  expires_at: string
+  paid_at?: string
+  completed_at?: string
+  refund_amount: number
+  refund_reason?: string
+  refund_requested_at?: string
+  refund_requested_by?: number
+  refund_request_reason?: string
+  plan_id?: number
+}
+
+// ==================== Plans & Channels ====================
+
+export interface SubscriptionPlan {
+  id: number
+  group_id: number
+  group_platform?: string
+  group_name?: string
+  rate_multiplier?: number
+  daily_limit_usd?: number | null
+  weekly_limit_usd?: number | null
+  monthly_limit_usd?: number | null
+  supported_model_scopes?: string[]
+  name: string
+  description: string
+  price: number
+  original_price?: number
+  validity_days: number
+  validity_unit: string
+  /** Stored as JSON string in backend; API layer should parse before use */
+  features: string[]
+  for_sale: boolean
+  sort_order: number
+}
+
+export interface PaymentChannel {
+  id: number
+  group_id?: number
+  name: string
+  platform: string
+  rate_multiplier: number
+  description: string
+  models: string[]
+  features: string[]
+  enabled: boolean
+}
+
+// ==================== Providers ====================
+
+export interface ProviderInstance {
+  id: number
+  provider_key: string
+  name: string
+  config: Record<string, string>
+  supported_types: string[]
+  enabled: boolean
+  payment_mode: string
+  refund_enabled: boolean
+  limits: string
+  sort_order: number
+}
+
+// ==================== Request / Response ====================
+
+export interface CreateOrderRequest {
+  amount: number
+  payment_type: string
+  order_type: string
+  plan_id?: number
+}
+
+export interface CreateOrderResult {
+  order_id: number
+  pay_url?: string
+  qr_code?: string
+  client_secret?: string
+  pay_amount: number
+  expires_at: string
+  payment_mode?: string
+}
+
+export interface DashboardStats {
+  today_amount: number
+  total_amount: number
+  today_count: number
+  total_count: number
+  avg_amount: number
+  daily_series: { date: string; amount: number; count: number }[]
+  payment_methods: { type: string; amount: number; count: number }[]
+  top_users: { user_id: number; email: string; amount: number }[]
+}