feat(mesh): show federated Archipelago nodes on the Mesh Map

Peers that opt in via a new "Share Location" toggle in Settings
(server.set-location RPC) get plotted on other trusted peers' Mesh Map
with a distinct Archy-logo marker, separate from raw LoRa radio peers.
Location is persisted locally, carried in NodeStateSnapshot, and
propagated through federation sync/delta like other node state.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

neode-ui/src/api/rpc-client.ts

@@ -721,6 +721,8 @@ class RPCClient {
         uptime_secs?: number
         tor_active?: boolean
         nostr_npub?: string
+        lat?: number | null
+        lon?: number | null
       }
     }>
   }> {