WAL-byte decode proves REAL data loss (not commit-index): committed prefix
entries physically absent from live nodes (ctrl-2 WAL starts LSN 16, ctrl-3 LSN
13), present only on the down node. Mechanism: empty-rejoin catch-up streams
[watermark..committed] not [1..], no snapshot to backfill the prefix -> permanent
gap. Predates libxce-failover. Full findings + open forks + xce_test waldump
tooling plan in INVESTIGATION-failover-job-loss.md. Not yet fixed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>