This is a quick fix to a problem that gives a confusing/poor initial
experience, as in this thread:
https://groups.google.com/g/moonfire-nvr-users/c/WB-TIW3bBZI/m/Gqh-L6I9BgAJ
I don't think it's a permanent solution. In particular, when we
implement an event stream (#40), I don't want to have a separate event
for every frame, so having the days map change that often won't work.
The client side will likely manipulate the days map then to include a
special entry for a growing recording, representing "from this time to
now".
459615a616