When invoking the angularjs method feedsFoldersSvc.add_feed, if the feed is already in the scope it is not added again (which would make it appear twice in the sidebar), but its unread_entries attribute is updated instead.
When a feed refresh job finishes successfully, its unread entries count is updated in the sidebar automatically.

Or, if the feed being refreshed is not in the sidebar right now, it is inserted there.
When dismissing a job status alert, better control of the case in which there are no job status update timers running.
When trying to display the feed title in a refresh feed job status alert, load the feed via Ajax if it's not in the scope.

The code has been written in such a way that loading a single feed is not attempted while the whole list of feeds is being loaded; and that while a single feed is loading, no further attempts are made to load it via Ajax.
While a feed has a refresh feed job status being displayed in the start page, it won't be removed from the sidebar even if it has no unread entries.
Since a9e0102b1cc38da172f1607667095e48c6d4a9c5 it is not necessary to use Bootstrap javascript to remove job status alerts. When the job status object is removed from the scope, the alert goes away.