Make VPN fabric telemetry carrier neutral

agents/rap-node-agent/cmd/rap-node-agent/main.go

@@ -2861,7 +2861,8 @@ func heartbeatPayload(cfg config.Config, identity state.Identity, meshState *syn
 			report := map[string]any{
 				"schema_version": "rap.vpn_fabric_session_transport_report.v1",
 				"enabled":        true,
-				"transport":      "fabric_session_websocket_binary_frames",
+				"transport":      "fabric_session_binary_frames",
+				"carriers":       []string{"quic", "websocket"},
 				"packet_payload": "rap.vpn_packet_batch.fabric.v1",
 				"gated":          true,
 				"observed_at":    observedAt.UTC().Format(time.RFC3339Nano),

agents/rap-node-agent/cmd/rap-node-agent/main_test.go

@@ -750,6 +750,7 @@ func TestHeartbeatPayloadIncludesMeshEndpointReport(t *testing.T) {
 	}
 	if report, ok := payload.Metadata["vpn_fabric_session_transport_report"].(map[string]any); !ok ||
 		report["packet_payload"] != "rap.vpn_packet_batch.fabric.v1" ||
+		report["transport"] != "fabric_session_binary_frames" ||
 		report["peer_sessions"] == nil {
 		t.Fatalf("vpn fabric session report missing: %+v", payload.Metadata)
 	}

docs/architecture/DISTRIBUTED_FABRIC_NODE_PROTOCOL_PLAN.md

@@ -333,6 +333,9 @@ bonus.
 Endpoint health observations are now emitted as a bounded standalone heartbeat
 report (`rap.vpn_fabric_endpoint_health_report.v1`) so control plane can ingest
 candidate feedback without parsing the transport diagnostics blob.
+VPN fabric-session transport telemetry is carrier-neutral
+(`fabric_session_binary_frames`) and reports QUIC/WebSocket as available
+carriers instead of describing the dataplane as WebSocket-only.
 
 Deliverables: