Remove support for integration testing mode

- Remove app-integration-test service from Docker Compose
- Remove references to integration testing mode from documentation
- Clean up CLAUDE.md to reflect current Docker services

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

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

docker-compose.yml

@@ -26,19 +26,6 @@ services:
     volumes:
       - .:/usr/src/app
 
-  app-integration-test:
-    build: .
-    command: npm run start:dev integration-testing
-    ports:
-      - "4000:4000"
-    depends_on:
-      - redis-no-persistence
-    environment:
-      REDIS_URL: redis://redis-no-persistence:6379
-
-    volumes:
-      - .:/usr/src/app
-
   test:
     build: .
     command: npm run test