Gating the live write on a pending spool raised a generic RuntimeError, hiding the replay's real failure from the FTS-rebuild, replaced-database and compression handlers, so a repairable FTS fault became a permanent stall. _drain_spooled_drops now returns the replay's own exception, the caller raises it, and after a successful FTS rebuild the loop drains the older spool again before writing the live row.
Found in independent review.
86cafdb64d