* perf(ports): run lsof without blocking on dead network mounts
Without -b, lsof stat()s every mounted file system before answering. A
hard-mounted network share that stops responding blocks that call in the
kernel, so each port scan left an unkillable lsof behind. Pass -b -w to
the lsof queries that name no file (port list, process cwd, executable
path); their output is unchanged. The -U and +D queries keep stat
because -b makes lsof reject named-file arguments.
Linear: STA-9017, STA-9716
* perf(ports): name the stuck lsof helper in the comment; plain readiness test name
* test: query a known child executable in lsof readiness smoke test
