The wanted-state read was a boot-time DAG node, so a swarm-level change sat
unapplied until the next restart. This watches the hive's own bucket and
converges on each update.
It does not replace the boot read: a watch hears only what is published while
it is listening, so a hive that was down still learns the current declaration
from `pull`. The watch is the fast path, `pull` stays the repair path.
Rides the connection swarm-status already opens, as a third consumer — a
second connect would double the auth-callout traffic and give the two paths
independent reconnect state, which is the reason the deploy-event drain is
spawned there too.
A delete is not a deletion order. `carries_a_declaration` is pure and tested
so that rule is enforced rather than asserted: converging on a withdrawn key
would tear down exactly the agents "absence is not a deletion order" protects.