The ten-second stall after a start is already gone

The archive fix that landed on main at 13:09 (“Looking up an archived card no longer builds the whole archive each time”) already removes the stall this card is about. No further code change is needed.

Startup sharing path
665 archived cards, 199 shared
Time
Before the fix (8d4ed733)4,089 ms
Now (5d49f738)15 ms

On this machine: Obeya restarted at 13:10:08 with the fix. ~/.obeya/stalls.log has had no new entry since; its last entry, at 13:09:58, came from the old code. Before, the stall came about 12 s after each start.

What is left: after any change to a card, the next lookup rebuilds the archive once (about 5 ms in the test). That only adds up in loops that write on every pass, and those are rare. Left as it is.