0006 — The table is named message_log, not jobs

Context. The build plan’s text calls the queue table jobs, but the code already uses message_log, and a deliberate log/queue split is planned that will be the natural moment to settle names.

Decision. Keep message_log and defer the rename to the log/queue split rather than renaming now.

Consequences. Naming diverges from the plan text in the interim; the table gets renamed at most once, at the moment its role is actually redefined, instead of twice.