START valid Linux A/B at unchanged b8482445. Original attempt is VOID under IR-107. New RUNNER_TEMP=/tmp/spt-consumer-304-b8482445-valid-dlxj5f1o; git -C there rev-parse --show-toplevel exits 128 with not-a-repository. Driver also checks every actual TEMP/TMP/TMPDIR after sandbox setup, refuses wrong SHA/dirty tree, and reaps only birth+exe+isolated-home anchored own survivors between phases. Same profile/default, CI env and verbatim HEAVY; same own warm target, no baseline/delta run. Authoritative new receipts will be consumer-linux/attempt2/.