A request opened on another AgentMux instance on this machine (a
cross-channel FleetBulkStop target, whose user is asked there): where
its status lives. status for these is proxied (see remote_for).
pending → proceeding, atomically, handing over the action to run:
exactly one of the window running out and the user’s Keep running wins
(ReAgent P1 on #3789 — checking and setting under separate locks let a
late check see pending after a keep).
Ask to shut block_id down, subject to the user’s override. A request
already pending — or under way — for the block is joined instead: the clock
never restarts, and no second window opens beside it (ReAgent P1 on #3789:
a second banner’s Keep running could not stop the first). A joiner whose
action does more (see Action::rank) replaces the pending action and is
named on the banner, so nobody is told the outcome of less than they asked
for (ReAgent P1 on #3798). The returned view says whose request it is: a
caller whose by/via differ has joined someone else’s.