To make installing as a PWA possible. Fixes #1181.

Also make it a number.

It still won't work behind a base path, but if you're using a reverse
proxy you can just redirect to HTTPS yourself. And should probably
handle TLS termination there too.

For sockets I just needed to add back the proxy call.

Just a login form and a list of applications. No modals or anything like
that.

Now it should work whether you have a trailing slash or not.

This is mostly for development where VS Code might not have finished
compiling yet.