Re-use the same Chrome profile directory

We use a new chrome profile via --user-data-dir, but we give it a new one each time. That means settings don't persist, you may have to re-authenticate, etc. We should remember that we created the directory, or keep it somewhere known.

And in fact it looks like this was done for webdev for #297 and we might just need to use that information.

Start by tracing how webdev creates and passes the Chrome --user-data-dir, then review the related implementation referenced in issue #297. The change is done when repeated runs reuse the same known profile directory so settings and authentication persist.

Written by the indexing model from the issue text.