how to clear the query history?

Hi,

this is pgadmin4, 6.11

when trying to open Query-Tool I get this error, and the tab is
opened empty and stale (unremoveable):

Failed to fetch Query History
Error: Minified React error #31;
visit
https://reactjs.org/docs/error-decoder.html?invariant=31&args[]=object%20with%20keys%20%7B%7D
for the full message

This happens only on a specific database. When I open Query Tool for
a different database, then switch the Tab back from "Query
History" to "Query", then it works again.

Using a different browser does not help, restarting the pgadmin4
server doesn't help either. Apparently that Query History data got
persistently botched.
Where is that stored, so I can clean it out?

This has apparently happened while I was trying to somehow enable
selection from firefox about:config. So when we're at it: is there a
way to enable selection in the editor?

This is a FreeBSD desktop, and we have two cut&paste tools:
- the selection: mark something with left-mouse, point somewhere else
and insert it with middle-mouse.
- the Clipboard: mark something with left-mouse, hit Ctrl-C. point
somewhere else and insert with Ctrl-V.

Both do normally work, the exception is the pgadmin4 editor, where
the selection appears to be disabled. Since my normal web application
editor (javascript only) does work nicely with both, this must be
something specific to pgadmin4.

-- PMc