feat: Интеграция DePay для криптовалютных платежей (USDT/Polygon)

- Добавлены endpoints для DePay: callback, success, rate, history
- Заменена система проверки чеков на CryptoPayment
- Переименована модель Check в CryptoPayment в Prisma схеме
- Обновлен billing.tsx для работы с DePay виджетом
- Все секреты вынесены в .env файлы
- Интеграция с CoinGecko API для курса USDT/RUB
- Добавлена RSA верификация webhook от DePay

ospabhost/backend/prisma/migrations/20260110_rename_check_to_crypto_payment/migration.sql

@@ -0,0 +1,19 @@
+-- Rename Check table to CryptoPayment
+RENAME TABLE `check` TO `crypto_payment`;
+
+-- Add new columns for crypto payments
+ALTER TABLE `crypto_payment` 
+  ADD COLUMN `transactionHash` VARCHAR(191) NULL,
+  ADD COLUMN `blockchain` VARCHAR(191) DEFAULT 'polygon',
+  ADD COLUMN `token` VARCHAR(191) DEFAULT 'USDT',
+  ADD COLUMN `cryptoAmount` DECIMAL(20, 8) NULL,
+  ADD COLUMN `exchangeRate` DECIMAL(10, 2) NULL COMMENT 'USDT to RUB rate',
+  ADD COLUMN `paymentProvider` VARCHAR(191) DEFAULT 'depay',
+  MODIFY COLUMN `status` VARCHAR(191) DEFAULT 'pending' COMMENT 'pending, completed, failed',
+  MODIFY COLUMN `fileUrl` VARCHAR(191) NULL COMMENT 'Not used for crypto payments';
+
+-- Update foreign key name if needed
+ALTER TABLE `crypto_payment` 
+  DROP FOREIGN KEY `check_userId_fkey`,
+  ADD CONSTRAINT `crypto_payment_userId_fkey` 
+    FOREIGN KEY (`userId`) REFERENCES `user`(`id`) ON DELETE CASCADE ON UPDATE CASCADE;

ospabhost/backend/prisma/schema.prisma

@@ -23,7 +23,7 @@ model User {
   isAdmin           Boolean                  @default(false)
   tickets           Ticket[]                 @relation("UserTickets")
   responses         Response[]               @relation("OperatorResponses")
-  checks            Check[]                  @relation("UserChecks")
+  cryptoPayments    CryptoPayment[]          @relation("UserCryptoPayments")
   balance           Float                    @default(0)
   notifications     Notification[]
   pushSubscriptions PushSubscription[]
@@ -46,16 +46,22 @@ model User {
   @@map("user")
 }
 
-model Check {
-  id        Int      @id @default(autoincrement())
-  userId    Int
-  amount    Float
-  status    String   @default("pending") // pending, approved, rejected
-  fileUrl   String
-  createdAt DateTime @default(now())
-  user      User     @relation("UserChecks", fields: [userId], references: [id])
+model CryptoPayment {
+  id              Int      @id @default(autoincrement())
+  userId          Int
+  amount          Float // Amount in RUB credited to balance
+  cryptoAmount    Float? // Amount in USDT paid
+  exchangeRate    Float? // USDT to RUB exchange rate at payment time
+  status          String   @default("pending") // pending, completed, failed
+  transactionHash String? // Blockchain transaction hash
+  blockchain      String   @default("polygon") // polygon, ethereum, bsc, etc.
+  token           String   @default("USDT") // USDT, USDC, ETH, etc.
+  paymentProvider String   @default("depay") // depay
+  fileUrl         String? // Not used for crypto payments (legacy from Check)
+  createdAt       DateTime @default(now())
+  user            User     @relation("UserCryptoPayments", fields: [userId], references: [id], onDelete: Cascade)
 
-  @@map("check")
+  @@map("crypto_payment")
 }
 
 model Service {