The owner watchdog (#132219) retires a detached serve --isolated backend once
backend.lock.json names a newer spawn, but it only trusts a lock whose logPath
ends in /<ownershipId>/<nonce>.log. Locks on native Windows SSH hosts are
written by windows_ssh_runtime.write_lock from the Desktop's record, which
carries no logPath, so read_valid_backend_lock returned None there and a
reconnect storm kept stacking backends.
write_lock now stamps the runtime's own log path for the lock's nonce, in
forward-slash form so the suffix check matches. All three Windows lock writes
(the in-mutex spawn record and the two Desktop updates) pass through it, and
the fix ships with the host install, so no Desktop rebuild is needed.
Refs #132034
2646293a20