When decnet.system.log is root-owned (e.g. created by a pre-fix 'sudo
decnet deploy') and a subsequent non-root process tries to log, the
InodeAwareRotatingFileHandler raised PermissionError out of emit(),
which propagated up through logger.debug/info and killed the collector's
log stream loop ('log stream ended ... reason=[Errno 13]').
Now matches stdlib behaviour: wrap _open() in try/except OSError and
defer to handleError() on failure. Adds a regression test.
Also: scripts/profile/view.sh 'pyinstrument' keyword was matching
memray-flamegraph-*.html files. Exclude the memray-* prefix.