Validators can now return enriched data via ValidationResult.accept_with()
instead of only accepting or rejecting operations. The engine applies
returned fields (contents, tags, tag_groups) to the operation parameters.
- Add accept_with() factory to ValidationResult with optional enrichment
fields: contents, tags, tags_match, tag_groups
- Add tags, tags_match, tag_groups to RecallContext so validators can
see current filter state
- Update _validate_operation to return ValidationResult
- Apply enrichment from result at all retain (2 sites) and recall call
sites in MemoryEngine
- Existing validators using accept()/reject() work unchanged