Create docker-compose.yml for local OceanBase development. Include:
- OceanBase CE 4.3.5 service with proper memory settings
- Health check that waits for database ready
- Volume for data persistence
- Environment variables for vector memory config
Also create docker-compose.seekdb.yml as a lightweight alternative using SeekDB image.

Create CONTRIBUTING.md with sections: Prerequisites, Development Setup (clone, poetry install,
docker-compose up), Running Tests (unit, integration, comprehensive), Code Style (ruff, mypy),
Submitting PRs (branch naming, commit messages, PR template). Reference the Makefile targets.

Create examples/ directory with working Python scripts:
1. quickstart.py - basic vector store usage (add docs, search)
2. rag_demo.py - simple RAG pipeline with LangChain
3. hybrid_search_demo.py - demonstrate sparse + dense + fulltext search
Each script should work with docker-compose setup and include comments explaining each step.

Update Makefile to add targets: docker-up, docker-down, docker-logs for managing local dev environment