agent/claude-usage/backfill-history.js runs by hand from the repo (never
from the cron install, the agent is unchanged). It rebuilds the closed days
with the agent's own aggregate() on past windows and writes { days } to the
--out file, which the server merges with `claude-usage-history.js --import`
(an already archived date wins).
Each 30-day window keeps only its 28 inner days and the next steps back 28
days, so a request straddling a window boundary is deduplicated by the
window that keeps it and counted once. The first window stops at D-2. The
walk is bounded by --max-windows (default 24) rather than guessed from file
mtimes, which say nothing of the oldest line a resumed session holds.
It never reads the credentials file, opens no connection, writes only the
--out file (mode 600, never overwritten) and prints counts only.
Refs #55
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
