admin: export upstream/peer relays in /state for the mesh view

[gmarzot]

The dashboard's "Peer Relays" table is a placeholder that lists only the local relay — /state has downstream_peers (observed empty so far) and nothing describing upstream/mesh peer relays this node connects to.

Ask: /state (or a sibling section) listing known peer relays: relay_id, address/hostname, direction (upstream/downstream), session state, and ideally per-peer session/subscription counts. The json-exporter maps it to moqx_peer_relay{...} series and the table populates with no dashboard redesign.

Context: mesh/peering is coming (LAPS #340); the dashboard slot is already reserved.

[afrind]

downstream_peers (observed empty so far)

I thought this worked around NAB?

[afrind]

Oh I see, we have it for downstream_peer but not upstream peers.