Centralized @ExceptionHandler(ObjectOptimisticLockingFailureException) net so
any write path losing a @Version race becomes a generic 409 (CONFLICT code) —
never a 500 + Sentry + Hibernate internals (CWE-209). No Sentry, class-name-
only parameterized logging, body free of id/version/class. Entity-agnostic by
design (no switch on getPersistentClassName); the service catch keeps the
precise TIMELINE_EVENT_CONFLICT. Per #775 Q2/R4/R8.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>