feat(server): add Prisma schema with all 8 data models

- User, CardType, Membership, WeekTemplate, TimeSlot, Booking, Order, StudioConfig
- PrismaService and global PrismaModule
- snake_case column mapping with camelCase TypeScript fields
- Proper indexes and unique constraints

packages/server/src/app.module.ts

@@ -1,6 +1,7 @@
 import { Module } from '@nestjs/common'
 import { ConfigModule } from '@nestjs/config'
 import { AppController } from './app.controller'
+import { PrismaModule } from './prisma/prisma.module'
 
 @Module({
   imports: [
@@ -8,6 +9,7 @@ import { AppController } from './app.controller'
       isGlobal: true,
       envFilePath: ['.env.local', '.env'],
     }),
+    PrismaModule,
   ],
   controllers: [AppController],
 })

packages/server/src/prisma/prisma.module.ts

@@ -0,0 +1,9 @@
+import { Global, Module } from '@nestjs/common'
+import { PrismaService } from './prisma.service'
+
+@Global()
+@Module({
+  providers: [PrismaService],
+  exports: [PrismaService],
+})
+export class PrismaModule {}

packages/server/src/prisma/prisma.service.ts

@@ -0,0 +1,16 @@
+import { Injectable, OnModuleInit, OnModuleDestroy } from '@nestjs/common'
+import { PrismaClient } from '@prisma/client'
+
+@Injectable()
+export class PrismaService
+  extends PrismaClient
+  implements OnModuleInit, OnModuleDestroy
+{
+  async onModuleInit() {
+    await this.$connect()
+  }
+
+  async onModuleDestroy() {
+    await this.$disconnect()
+  }
+}