Supports:
- Reading the head of a log
- Reading the tail of a log
- Following a log in one of two ways:
- Streaming the HTTP request (using fetch res.getReader)
- Polling the log endpoint (using EC timeouts)
- When a list 403s, treat it as if it were empty
- When a single resource 403s, redirect to an application error page
that has a backdoor link to the tokens page
