chore: remove unused data_dir / DATA_DIR (Storage Bucket dependency)

fix(neo4j): move data dirs from /data (S3 FUSE) to /tmp (local)

debug(spaces): HEALTHCHECK + neo4j logs to stdout for HF health check diagnosis

fix(api): ensure health checks always return 200 for HF Spaces

refactor(extractor): migrate to Responses API (client.responses.create)

fix(extractor): max_tokens -> max_completion_tokens for gpt-5-mini, bump openai>=1.84.0

refactor(extractor): remove heuristic fallback, require OpenAI API key

feat(sample): switch Load Sample to Japanese supply chain text

feat(nlp): add Japanese language support

fix(api): run Neo4j init as background task so FastAPI responds immediately

feat: implement CC-RAG prototype with Neo4j, FastAPI, React