The #87331 remaining half: when hermes.exe (or a sibling shim) could not
be renamed aside, the updater printed a warning and ran the installer
anyway — which died partway on the same locks and stranded the venv
between versions.
- _run_quarantined_install gains strict_quarantine: any shim whose
rename failed every retry aborts BEFORE the install command runs
(successful renames rolled back), raising ShimQuarantineError.
- The update dependency sync passes strict_quarantine=True. The update
boundary turns the error into a refusal: defer via the
update-incomplete marker, exit 2 (recorded as refused by the receipt
net), never ZIP-fallback. Post-sync repair installs keep warn-and-try
(their venv is already mutated; refusing buys nothing).
- The recovery installer (_install_repair._run_install_cmd) is strict
unconditionally: marker survives, next launch retries after the
holder exits.
- Live Windows E2E for the wine2e lane: a real child holds hermes.exe
without FILE_SHARE_DELETE (the exact field lock shape), strict path
refuses with zero installer invocations, releases roll back, and the
same path proceeds once the holder exits.
Sabotage-verified: reverting the strict wiring makes both fail-closed
tests fail.
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