Description
The hot store holds 90 days and the cold NFS tree holds everything. Backfill is the reason this project beats native telemetry, and an unbounded run double counts every window where native was also live.
Acceptance Criteria
- #1 -backfill-since and -backfill-until are both required together and an unbounded run is impossible
- #2 Backfill uses the same checkpoint discipline and never corrupts live progress
- #3 Output carries codingagent.backfill
- #4 Backfill throughput is measured and recorded so a full-history run can be planned rather than guessed
- #5 A backfill run over a window is idempotent: running it twice does not double the series
Definition of Done
- #1 just check passes: fmt-check, lint, build, test-short, probe-ci, dashboard-check and docs-links all clean