Shove a bunch of stuff in notebook tabs, add a few
affordances (e.g. github and frontend links, links from m2m), surface
a few missing fields.
Hopefully makes the backend form both easier to navigate and easier to
administrate from.
Displays the entire batch set as a table, along both
repository (linked PRs) and branch (forward ports). Should provide a
much more complete overview.
Adds a copy of the dashboard as a raster render, to link from the PR:
as usual SVG is shit, content-based viewboxes are hell and having to
duplicate the entire CSS because `<img/>`-linked CSS can't run is
gross. And there's no payoff since the image is not interactible
anyway.
Performing manual ad-hoc table rendering via pillow is not
significantly worse, it works fine and it's possible to do *really*
good conditional request handling (hopefully) because I've basically
got all the information I need right here.
In fact it might make sense to upgrade the regular HTML page with
similar conditional request handling, at least for the last-update
bit if not the etag.
Fixes #771,fixes #770
