0.3.2

Add v3 data model with EntityType and relationship fields

- Add EntityType union type with 10 fixed entity types
- Add entityType field to OntologyNode (replacing flexible labels)
- Add relationship field to OntologyEdge (free-form verbs)
- Add helper functions: getEntityTypeColor, getNodeEntityType, getEdgeRelationship
- Add labelToEntityType for legacy v2 data migration
- Update prompts for v3 extraction format
- Update search to use new type helpers

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>