Take over link handling #2

The intersection of service workers and sandboxing is unkind to links. Instead, we need to intercept links in the shuttle and:

• If it's a hash link, scroll
• If it's a link to something in the tile, navigate to that (update the src directly)
• If it's an external link, open it in a new tab

This may allow us to restrict the sandbox some more since loosening navigation barely helps.