Replace a project's GEO settings

Writes the full settings document and re-arms the recurring scan. Engines must be ids from the model catalog this organization can see (the ones GET /geo/settings returns) and languages must be supported languages; an unknown value is rejected with a 400 instead of being replaced by a default. Zero data retention is forced off without the ZDR add-on, and engines that are not visible to this caller keep their stored selection. Competitors are managed through the competitors endpoints and are not part of this payload.