TODO
-[x] respect order of queue
-[x] replacements
-[x] those w/o completion handler
-[x] basic send+log operation persists
-[x] send+ui completion
-[x] share extension
-[x] update state jobs
-[x] App Lifecyle
-[x] settable
-[x] Mark as ready on startup
-[x] Fail appropriate jobs on startup
NICE TO HAVE
-[x] concurrent per senders
-[ ] longer retry (e.g. 24hrs)
-[ ] App Lifecyle
-[x] retry failed jobs on startup?
-[ ] reachability
DONE
-[x] basic passing test
-[x] datamodel
-[x] queue/classes
