CORRECTION: initial Linux Phase A at b8482445 is VOID, not candidate-red. My driver placed RUNNER_TEMP/TMPDIR/TMP under the checkout (.spt/preserved/.../runner-temp). Both daemon assertions explicitly identify the IR-107 fixture-premise violation; derivation_ladder resolved the enclosing repo too. No main delta has started. Original logs/exit 100 retained; this is a harness environment failure. Six run-owned PIDs already reaped with exe+birth+isolated-home proof. I will verify a /tmp root is outside all Git toplevels, rerun A then B at unchanged SHA, and register this instance under IR-107.