DC-095 masks emails at every live log sink; the rotated archive was the
remaining belt-and-braces gap — any future sink that forgets masking would
persist raw PII in error.log.1 for a full rotation cycle. appendErrorLog
now scrubs the freshly rotated archive with the SAME canonical mask
(sa****@example.com) via atomic rewrite (sibling .redact-<pid> temp, wx
open preserving mode else 0600, fsync, rename). Scrub failure is caught
and logged; the new error line is still appended. Stale crash-leftover
.redact-<pid> temps are swept best-effort on every rotation. Also
documents scripts/redact-log-pii.js usage in README (queue item e).
Judge: GLM-5.3 cold read (deleg_e7cd7f8c), round-1 grade B ship — both
nits addressed in-commit: stale-temp sweep (new 5th test pins it),
quoted-local-part mask edge deferred as pre-existing DC-095 primitive.
Tests: 122 suites / 2790 green (+5 DC-108 pins; was 2785 post-DC-107).
