fix: Standardize container names with site11_ prefix

- Changed notifications-backend container name to use _notifications_backend
- Changed statistics-backend container name to use _statistics_backend
- Now all containers have consistent site11_ prefix for better organization

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docker-compose.yml

@@ -196,7 +196,7 @@ services:
     build: 
       context: ./services/notifications/backend
       dockerfile: Dockerfile
-    container_name: site11-notifications-backend
+    container_name: ${COMPOSE_PROJECT_NAME}_notifications_backend
     ports:
       - "8013:8000"
     environment:
@@ -282,7 +282,7 @@ services:
     build: 
       context: ./services/statistics/backend
       dockerfile: Dockerfile
-    container_name: site11-statistics-backend
+    container_name: ${COMPOSE_PROJECT_NAME}_statistics_backend
     ports:
       - "8012:8000"
     environment: