In 49d6d2f as part of #813 I removed the allow_sql setting - on the basis that users could disable the ability to execute custom SQL queries using the new permission system instead.

I don't think this was the right decision. Disabling custom SQL is an important security capability, and explaining how to do it using permissions is significantly more complex than letting people know they can add --setting allow_sql off.

So I want to bring that setting back - maybe with a different, better name - and have it modify the default for that option if the permissions system doesn't have an opinion.

That way people can still use the setting but then use permissions to allow specific signed-in users access to execute SQL.