- Add yachtId (optional) to createInterestSchema + listInterestsSchema
(updateInterestSchema inherits it via partial() automatically).
- Add assertYachtBelongsToClient helper that accepts direct client
ownership OR company-represented clients with an active membership
in the owning company.
- createInterest + updateInterest validate yacht ownership whenever
yachtId is supplied/changed.
- changeInterestStage rejects moving out of stage=open with yachtId
null (ValidationError).
- listInterests filter supports yachtId.
- Integration tests cover all 7 paths; validator test for yachtId.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
