feat(db): add Prisma schema and global PrismaModule

Models mirror Hiboutik entities (categories tree, brands, suppliers, products and their versions, customers) plus addresses and orders for the upcoming sync. Every synced model is matched with Hiboutik through a unique hiboutikId. The generated client is ignored by git and env files other than .env.example are ignored.

prisma/prisma.service.ts

@@ -0,0 +1,20 @@
+import { Injectable, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
+import { PrismaClient } from './generated/client';
+import { PrismaPg } from '@prisma/adapter-pg';
+
+/** Prisma client shared by the whole app (global PrismaModule), connected to `DATABASE_URL` through the pg driver adapter. */
+@Injectable()
+export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
+  constructor() {
+    const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL });
+    super({ adapter });
+  }
+
+  async onModuleInit() {
+    await this.$connect();
+  }
+
+  async onModuleDestroy() {
+    await this.$disconnect();
+  }
+}