A DST sweep that shuns artifacts (forcing a delta base, a manifest and a mid-chain artifact across seeds), reclaims through rewriteAndSwap, and cuts the run at sampled write/sync/rename boundaries. The oracle classifies the recovered store as the PRE image or the POST image and fails on anything else.

It earns its place: deleting packLog's pre-rename fsync is caught by this sweep and by nothing else in the suite. The concurrency-guard boundary is a second, DST-shaped pin on S3's fresh-stat fix rather than first coverage, and the module header says so.

Two oracle clauses are graded honestly as tripwires, not coverage. Surviving content is re-hashed by packLog before its own commit, so a defect that would corrupt it aborts the rewrite instead and the sweep just sees the PRE image; no mutant can make that clause fire. The PRE half of the third clause is subsumed by the byte-equality check. Both are kept cheap and labelled.

rewriteAndSwap and RewriteError are now pub: the property under test is a property of that sequence and reaching it needs the seam.

faulty_dir gains fileSetLength and fileClose wrappers, deliberately ungated so no sibling sweep's cut numbering shifts.

The default dst gate grows about 11s (~9%) for 12 sampled cuts per seed. check-in: cb22503707 user: dmestas tags: shun-implementation