370b593217
Upsert methods now RETURNING all struct columns and scan the result back into the pointer receiver, keeping the caller in sync with the actual DB state (id, created_at, etc. from the existing row on conflict). Insert detection compares the saved original ID with the returned ID instead of relying on the PostgreSQL-internal xmax column. Signed-off-by: Émile Ré <emile@probo.com>