Audit smoke, soak, profiling, and benchmark harnesses for account daemon runtime isolation

[astandrik]

Follow-up to #1691 and #1695.

PR #1695 isolates the focused security, watchdog, worker, and hook entry points that reproduced the account daemon shutdown. The longer-running smoke, soak, profiling, and benchmark harnesses have different lifecycle and measurement contracts, so they should be audited separately instead of expanding that fix.

Scope

• scripts/smoke-local.sh and scripts/smoke-test.sh
• scripts/soak-legs.sh and scripts/soak-test.sh
• scripts/memlab.sh, scripts/memlab-drive.py, and scripts/memlab-report.py
• scripts/benchmark-index.sh, scripts/benchmark-search-graph.sh, and scripts/clone-bench-repos.sh

Invariants to check

• An inherited CBM_RUNTIME_DIR or CBM_CACHE_DIR is never reused for a product process started by a harness.
• Concurrent harness runs receive different private roots.
• Unix roots are owner-only. Windows runs use the repository's protected temp-root helper rather than duplicating ACL logic.
• Install, update, uninstall, restart, and daemon cleanup stay inside the harness runtime.
• A sentinel client in account runtime A remains connected with the same daemon PID and generation, and runtime A records no activation_shutdown.
• A harness stops its own child processes before cleaning its runtime. If its private daemon remains active, cleanup leaves the root for diagnosis.
• Runtime isolation does not alter benchmark coverage or invalidate timing comparisons. Any performance claim includes comparable setup, cache, and total wall-clock measurements.

Expected output

For each entry point, record whether it already satisfies these invariants. Add a focused fail-before reproduction for every confirmed gap, then submit scoped fixes separately from #1695.

[DeusData]

Thank you for separating this audit from the focused fix in #1695. The boundary is correct: smoke, soak, profiling, and benchmark harnesses have lifecycle and measurement contracts that should not be folded into the security-script repair.

Please keep this issue as the audit ledger. Each confirmed isolation failure should have its own deterministic reproduction and focused fix, especially where changing setup could affect benchmark comparability. That gives every harness change an attributable reason and prevents a broad test-infrastructure sweep from becoming one unreviewable PR.