createdBy/updatedBy are NOT NULL and createdAt/updatedAt/version are Hibernate-
populated on every persisted row, so per the CLAUDE.md rule they must carry
@Schema(requiredMode = REQUIRED) like id/title/type/eventDate/precision already
do. Keeps the generated TypeScript types honest if the entity ever reaches the
OpenAPI spec (responses in #775 are planned as views, per ADR-040).
Extends the #774 task list (which named only the five domain fields) per PR #816 review.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>