Mirror job timestamps are stored to the second. A sync that starts and
finishes in the same second writes its "syncing" and "synced" events
with the same timestamp, and SQLite returned the tie oldest first, so
the summary took the start event as the repository's current state.
The activities and dashboard queries break ties on rowid, newest first,
and the summary counter prefers a finish over a start from the same
second whatever order they arrive in.