fix: set POSTGRES_DB in E2E compose for future CRUD tests

Author: devin-ai-integration[bot]

src/docker-compose.e2e.yml

@@ -27,6 +27,7 @@ services:
     ports:
       - "5432:5432"
     environment:
+      POSTGRES_DB: customerdb
       POSTGRES_PASSWORD: postgres
     volumes:
       - postgres_data:/var/lib/postgresql/data