Rewrite consolidation prompt rules to produce clean, single-facet observations:
- One observation per distinct facet (count, named entity, relationship)
- Match updates by entity/facet, not topic similarity
- No computation — never infer/calculate values not explicitly stated
- Cascade state changes to all affected observations
- Preserve event history (sold, died, moved) — conservative deletes
- Include dates on state changes when available
- Keep observations concise — no cross-facet narrative bloat
Add test_horse_observations.py exercising a realistic sequence of retain
operations (farm with horses being named, sold, dying) and verifying that
observations track history correctly and mental models can synthesize them.
