feat: add Prisma configuration file and update Dockerfile to include it

backend/src/prisma/prisma.service.ts

@@ -8,6 +8,10 @@ export class PrismaService
 {
   private readonly logger = new Logger(PrismaService.name);
 
+  constructor() {
+    super({ datasourceUrl: process.env.DATABASE_URL });
+  }
+
   async onModuleInit() {
     const maxAttempts = 10;
     const delayMs = 3000;