fix: Update database configuration for proper container naming

- Fix database name reference in docker-compose.yml
- Update config.go to use consistent database name
- Ensure database connection string matches container setup

docker-compose.yml

@@ -5,7 +5,7 @@ services:
     image: postgres:15-alpine
     container_name: bookmann_db
     environment:
-      POSTGRES_DB: ebookdb
+      POSTGRES_DB: bookmann
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: ${DBPASS}
     volumes:
@@ -31,7 +31,7 @@ services:
       DATABASE_PORT: 5432
       DATABASE_USER: postgres
       DATABASE_PASSWORD: ${DBPASS}
-      DATABASE_NAME: ebookdb
+      DATABASE_NAME: bookmann
       JWT_SECRET: ${JWT_SECRET}
       SERVER_PORT: 8765
     ports:
@@ -50,4 +50,4 @@ services:
       - .env
 
 volumes:
-  postgres_data:
+  postgres_data: