PR #24500 introduced stale-lock detection that calls
`_looks_like_gateway_process` to confirm a running PID is not an
unrelated process that reused the slot. On Windows neither `/proc`
nor `ps` is available, so `_read_process_cmdline` always returns
`None` and `_looks_like_gateway_process` always returns `False` —
causing every valid Windows gateway lock to be marked stale and
immediately evicted.
Fix: after `_looks_like_gateway_process` returns `False`, call
`_read_process_cmdline` directly. If the result is non-`None` the
live cmdline was readable and confirms the PID is foreign → stale.
If it is `None` (cmdline unreadable, e.g. Windows without ps), fall
back to `_record_looks_like_gateway` which validates the stored
`argv` the gateway wrote into the lock file at startup. Both
oracles must say "not a gateway" before the lock is evicted — the
same two-oracle pattern already used in `get_running_pid` (line 941).
Adds a regression test that simulates a Windows host where
`_looks_like_gateway_process` returns `False` for every PID and
`_read_process_cmdline` returns `None`, confirming the lock is kept
when the record's argv identifies it as a gateway process.