feat: implement payment service with error handling and validation

Add new payment service with repository, error handling, and validation
Add exceptions package with database and validation utilities
Update database package with new schema and zod types
Add turbo start script for development

packages/database/prisma/schema.prisma

@@ -9,6 +9,22 @@ generator client {
   output   = "../generated/prisma"
 }
 
+generator zod {
+  provider                 = "zod-prisma-types"
+  output                   = "../generated/zod"
+  writeBarrelFiles         = false // default is true
+  createInputTypes         = false // default is true
+  createModelTypes         = true // default is true
+  addInputTypeValidation   = false // default is true
+  addIncludeType           = false // default is true
+  addSelectType            = false // default is true
+  validateWhereUniqueInput = false // default is true
+}
+
+generator json {
+  provider = "prisma-json-types-generator"
+}
+
 datasource db {
   provider = "postgresql"
   url      = env("DATABASE_URL")
@@ -31,4 +47,62 @@ model TelegramUser {
   isPremium    Boolean?
   createdAt    DateTime @default(now())
   updatedAt    DateTime @updatedAt
+
+  payments Payment[]
+  subscription Subscription?
+}
+
+model Payment {
+  id             String        @id @default(cuid())
+  telegramUserId String
+  amount         Decimal       @db.Decimal(10, 2)
+  currency       String        
+  status         PaymentStatus @default(PENDING)
+  provider       String
+  providerId     String?
+  metadata       Json?
+  createdAt      DateTime      @default(now())
+  updatedAt      DateTime      @updatedAt
+  telegramUser   TelegramUser  @relation(fields: [telegramUserId], references: [id])
+}
+
+enum PaymentStatus {
+  PENDING
+  COMPLETED
+  FAILED
+  REFUNDED
+}
+
+model Plan {
+  id               String  @id @default(uuid())
+  code             String  @unique()
+  name             String
+  description      String?
+  durationDays         Int
+  dailyGenerations Int
+  price            Int
+  currency       String
+
+  subscriptions Subscription[]
+
+  @@index([code])
+}
+
+model Subscription {
+  id        String   @id @default(uuid())
+  telegramUserId    String   @unique
+  planId    String
+
+  startedAt       DateTime        @default(now())
+  expiresAt DateTime
+  canceledAt      DateTime?
+
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+
+  plan Plan @relation(fields: [planId], references: [id], onDelete: Cascade)
+  telegramUser TelegramUser @relation(fields: [telegramUserId], references: [id], onDelete: Cascade)
+
+  @@index([telegramUserId])
+  @@index([planId])
 }