Owner report: created a set, 'Interrupted (server restarted)' showed
on list + set views, generation proceeded and overwrote it. The
sweep's 'generating + no registry row' test had a false-positive
mode: it ran at EVERY pipeline instantiation, and an instance could
evaluate against a registry whose fresh row it couldn't observe.
Three guards, per ruling:
1. HEARTBEAT: ProblemSet.updatedAt? (contract + doc) — bumped on
every store write; createSet stamps it = createdAt; saveSet
re-stamps (validator tolerates absence for legacy rows).
2. ONCE PER PROCESS: the sweep guards on globalThis
.__lhPracticeSweepDone — no instance re-evaluates after the
process's first sweep.
3. GRACE WINDOW: only sets whose heartbeat (updatedAt ?? createdAt)
is older than 120s are stamped. A live run saves at every phase/
problem transition, so it is structurally unreachable; a true
orphan is minutes stale at next boot. One [practice <id>] log
line per stamped set (the extraction/jobs console.error idiom).
Tests: stale orphan stamped; FRESH generating set untouched (grace);
once-guard (second factory instantiation never re-sweeps); live-row
protection re-armed via resetSweep() test seam; store pins for
updatedAt birth-stamp + re-stamp + legacy tolerance. Architecture.md
sweep sentence updated (once-per-process + grace semantics).
1142/1142, tsc 0, lint 0, build 0.
amosblomqvist
8d39f3717c