Expose outbound traffic totals and simplify Direct chart breakdown

test/server/device-inventory.test.js

@@ -548,13 +548,32 @@ test('device outbound history keeps sing-box routes and kernel Direct on separat
     }),
   });
 
-  assert.deepEqual((await service.refresh()).devices[0].outboundTrafficHistory, []);
+  let snapshot = await service.refresh();
+  assert.deepEqual(snapshot.devices[0].outboundTraffic, {
+    observedAt,
+    singboxObservedAt: observedAt,
+    directIpv4ObservedAt: observedAt,
+    vpnBytes: '300',
+    directTrackedBytes: '30',
+    directIpv4Bytes: '100',
+    unknownBytes: '3',
+  });
+  assert.deepEqual(snapshot.devices[0].outboundTrafficHistory, []);
   observedAt = '2026-08-12T12:00:15.000Z';
   vpn = ['150', '250'];
   trackedDirect = ['30', '50'];
   unknown = ['4', '8'];
   directIpv4 = ['70', '90'];
-  let snapshot = await service.refresh();
+  snapshot = await service.refresh();
+  assert.deepEqual(snapshot.devices[0].outboundTraffic, {
+    observedAt,
+    singboxObservedAt: observedAt,
+    directIpv4ObservedAt: observedAt,
+    vpnBytes: '400',
+    directTrackedBytes: '80',
+    directIpv4Bytes: '160',
+    unknownBytes: '12',
+  });
   assert.deepEqual(snapshot.devices[0].outboundTrafficHistory, [{
     observedAt,
     vpnBytes: '100',
@@ -570,6 +589,15 @@ test('device outbound history keeps sing-box routes and kernel Direct on separat
   unknown = ['0', '1'];
   directIpv4 = ['5', '6'];
   snapshot = await service.refresh();
+  assert.deepEqual(snapshot.devices[0].outboundTraffic, {
+    observedAt,
+    singboxObservedAt: observedAt,
+    directIpv4ObservedAt: observedAt,
+    vpnBytes: '7',
+    directTrackedBytes: '3',
+    directIpv4Bytes: '11',
+    unknownBytes: '1',
+  });
   assert.deepEqual(snapshot.devices[0].outboundTrafficHistory.at(-1), {
     observedAt,
     vpnBytes: '0',
@@ -578,6 +606,7 @@ test('device outbound history keeps sing-box routes and kernel Direct on separat
     unknownBytes: '0',
   });
   assert.doesNotMatch(fs.readFileSync(filePath, 'utf8'), /outboundTrafficHistory/);
+  assert.doesNotMatch(fs.readFileSync(filePath, 'utf8'), /outboundTraffic/);
 });
 
 test('global traffic stays monotonic when a device expires and returns in the same epoch', async (t) => {