reduces api calls on build, services, graph, and repo pages
avoids calls when builds are finished
now with user agent

going to save this for a non-patch update

see #104

…d of checking build status

to make tab alerting work on errors; when this page was reduced to only
produce one call to update hooks, it didn't update tab status because
that's handled by the upper-level layout. this adopts same pattern as
source repos

this step won't update if it's not running

will redirect to last page you were on. some opportunity here to improve
messaging on login screen, or maybe sticky toast signaling reason you
are not on the page you were on before.