Ported from #1949, which surfaces the manual recovery steps the maintainer had
been giving out by hand instead of leaving the user with a raw Lucene error.
Adapted to the failure now being contained: with the exception no longer escaping
into the library change, the scan-failure catch blocks #1949 hooked would never
see it, and hooking only those would still miss every other trigger -- removing
books is what crashed the GUI. So the guard moves from AppScaffolding into
SearchEngineCommands next to the update commands it protects, and raises
UpdateFailed from there. Both GUIs subscribe, so any trigger is covered, and the
event carries the exception rather than needing #1949's StackTrace string sniffing
to find it. The dialog is shown once per session: a damaged index fails on every
library change and these steps only need following once.
Co-authored-by: rmcrackan <rmcrackan@gmail.com>
Previously, only some calls to ApiExtended.CreateAsync() would prompt users to login if necessary. Other calls would only work if the account already had a valid identity, and they would throw exceptions otherwise.
Changed ApiExtended so that the UI registers a static ILoginChoiceEager factory delegate that ApiExtended will use in the event that a login is required.
There are multiple subscribers to LibraryCommands.LibrarySizeChanged, and each one calls GetLibrary_Flat_NoTracking(). Passing the full library as an event argument speeds up all operations which happen after the library size changes.
Fix initial backup counts
