New GET /api/swarm on swarm-controller, backed by
services.hyperhive.swarm.name (SWARM_CONTROLLER_NAME env var, same
optionalAttrs-gated-on-option-resolving shape queueEnv/forgeEnv/etc.
already use). swarm-ui's <Shell> fetches it once and sets both
document.title and the header's brand text; falls back to the
existing static "hyperhive swarm" label when the operator never set
a name or the fetch fails.
Extracted the swarm-queue connect block out of main() into its own
connect_status_reader() fn to keep main() under clippy's line-count
lint after adding the new field wiring — no behavior change, same
comments moved as-is.
3643eccf22