MonitorLinkExpression kept a string_view of the string it was built
from, Monitor::linked_monitors_string, and the tokens parse() builds are
views into it. Monitor::Reload() calls Load(), which reassigns that
string without re-parsing the expression, so once the new value no
longer fits the old buffer every token points into freed memory. They
are read by the Debug(1, ...) calls in MonitorLinkExpression::visit(),
which runs on every analysed frame of a monitor with LinkedMonitors set
when its debug level is 1 or more.
Copy the string into the expression and point the views at the copy.
fixes#5271
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
