DeckyFleet now branches on /system/deployment-mode: in swarm mode it
pulls /swarm/deckies and normalises DeckyShardView into the shared
Decky shape so the same card grid renders either way. Swarm cards gain
a host badge (host_name @ address), a state pill (running/degraded/
tearing_down/failed/teardown_failed with matching colors), an inline
last_error snippet, and a two-click arm/commit Teardown button lifted
from the old SwarmDeckies component. Mutate + interval controls are
hidden in swarm mode since the worker /mutate endpoint still 501s —
swarm-side rotation is a separate ticket.
Drops the standalone /swarm/deckies route + nav entry; SwarmDeckies.tsx
is deleted. The SWARM nav group keeps SwarmHosts, Remote Updates, and
Agent Enrollment.