`UpdateLog` short-circuits on `len(Rows)==0` before honoring `NoMore`,
so a final empty `UpdateLog{NoMore:true}` never runs `TransferLogs`. The
task's `dbfs_data` rows are then never moved to log storage and never
deleted.
Fix: let `NoMore=true` with no new rows fall through to `TransferLogs`.
Bail when the runner has outrun the server (`Index > ack`) even with
`NoMore`, since archiving a log with a gap is worse than retrying.
Always call `WriteLogs` so `offset==0` bootstraps an empty DBFS file in
the no-output case (otherwise `TransferLogs` would fail at `dbfs.Open`).
Fixes: https://github.com/go-gitea/gitea/issues/37623
Ref: https://gitea.com/gitea/runner/pulls/952
Ref: https://gitea.com/gitea/runner/pulls/950
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
