- Add embedding column to kg_entities with HNSW index
- Generate entity embeddings during IngestExtraction
- Hybrid search in SearchEntities (ILIKE 0.3 + vector 0.7)
- Add team_id scope for shared KG across team members
- Add IsSharedKG/WithSharedKG context helpers
Closes#327
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>