Address Copilot code review feedback

Fixes applied:
- Fix NEO4J_PLUGINS JSON syntax in docker-compose.yml
- Fix directory name mismatch in README.md
- Remove unused imports (Any, Optional), add re and os
- Use Tuple from typing instead of lowercase tuple
- Move 're' import to module level (PEP 8)
- Configure Ollama client with OLLAMA_HOST env var for Docker
- Fix Cypher injection: use parameterized query for hops
- Make CONTAINS queries case-insensitive with toLower()
- Add try-finally block to ensure graph.close() on exceptions

rag_tutorials/knowledge_graph_rag_citations/docker-compose.yml

@@ -9,7 +9,7 @@ services:
       - "7687:7687"  # Bolt
     environment:
       - NEO4J_AUTH=neo4j/password
-      - NEO4J_PLUGINS=["apoc"]
+      - NEO4J_PLUGINS='["apoc"]'
     volumes:
       - neo4j_data:/data
     healthcheck: