Fetching lives in the component (mara's steer on hyperhive#2812) — a
host that needs the raw node list for something the generic tree
doesn't show (a count badge, a live-log panel keyed on a specific
node) now listens for this bubbling/composed CustomEvent instead of
doing its own parallel fetch. Fires from both the self-fetch path
(refresh()) and a host-pushed render(nodes) call, so a listener sees
every update regardless of source.
Verified via jsdom: both paths dispatch with the correct nodes in
detail.
98957b48e9