saveAndGet

Same write path as save, but returns the entity actually persisted — with any @GeneratedUuid/@CreatedAt/@UpdatedAt/@Version values injectTimestamps/ injectInitialVersion generated before the write, instead of discarding that copy the way save does. See GH #132 / ISS-096: callers who relied on save()'s Unit return and then reused their original entity (e.g. to build an HTTP response) were silently working with placeholder values — UUID(0, 0), Instant.EPOCH — while the row that actually landed in Scylla carried the real generated ones.