create/update/delete write methods (@Transactional) + getEvent read
(@Transactional(readOnly=true) for the LazyInit guard). Persons resolved via
PersonService.getAllById with a distinct-size check; documents via per-id
DocumentService.getDocumentById loop; both dedupe-first, fail-closed. RANGE
invariant (both directions), title-length guard, YEAR date normalization, and
default precision. Audit fields server-set (createdBy+updatedBy on create;
only updatedBy on update). Optimistic-lock conflict translated to
TIMELINE_EVENT_CONFLICT via saveAndFlush+catch. Views assembled after flush.
Per #775 / ADR-040.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
c51fc5e79f