From rough MVP to v2 and v3

The initial approach wasn't satisfying enough. It worked well for some sites but didn't catch enough cases. Who would have thought there are dozens of different ways to implement single-sign-on into a website? A better approach had to be found.

In a chat with @tompec we discussed a better algorithm and started coding v2 and v3. Squeezed between regular client work I had short nights until I had a version that worked on most websites.