fix(tracing): Fix existing-span update for both TTID and TTFD, add combined-use test

Broaden the TTID existing-span update condition to match the TTFD fix,
preventing duplicate spans when a component span with ok/undefined
status exists alongside a native timestamp. Add test for combined
<TimeToFullDisplay> component + reportFullyDisplayed() usage.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: antonis

packages/core/src/js/tracing/integrations/timeToDisplayIntegration.ts

@@ -141,7 +141,7 @@ async function addTimeToInitialDisplay({
   const manualDurationMs = (ttidEndTimestampSeconds - transactionStartTimestampSeconds) * 1000;
   const manualStatus = isDeadlineExceeded(manualDurationMs) ? 'deadline_exceeded' : 'ok';
 
-  if (ttidSpan?.status && ttidSpan.status !== 'ok') {
+  if (ttidSpan) {
     ttidSpan.status = manualStatus;
     ttidSpan.timestamp = ttidEndTimestampSeconds;
     debug.log(`[${INTEGRATION_NAME}] Updated existing ttid span.`, ttidSpan);

packages/core/test/tracing/timetodisplay.test.tsx

@@ -1153,6 +1153,46 @@ describe('reportFullyDisplayed', () => {
     expectFullDisplayMeasurementOnSpan(client.event!);
   });
 
+  test('does not create duplicate span when component and imperative API are both used', async () => {
+    const ttidTimestamp = nowInSeconds();
+    const ttfdTimestamp = nowInSeconds();
+
+    startSpanManual(
+      {
+        name: 'Root Manual Span',
+        startTime: secondAgoTimestampMs(),
+      },
+      (activeSpan: Span | undefined) => {
+        startTimeToInitialDisplaySpan();
+        startTimeToFullDisplaySpan();
+
+        render(<TimeToInitialDisplay record={true} />);
+        render(<TimeToFullDisplay record={true} />);
+
+        mockRecordedTimeToDisplay({
+          ttid: {
+            [spanToJSON(activeSpan).span_id]: ttidTimestamp,
+          },
+          ttfd: {
+            [spanToJSON(activeSpan).span_id]: ttfdTimestamp,
+          },
+        });
+
+        reportFullyDisplayed();
+
+        activeSpan?.end();
+      },
+    );
+
+    await jest.runOnlyPendingTimersAsync();
+    await client.flush();
+
+    const ttfdSpans = client.event!.spans!.filter((s: SpanJSON) => s.op === 'ui.load.full_display');
+    expect(ttfdSpans).toHaveLength(1);
+    expect(ttfdSpans[0]!.status).toBe('ok');
+    expectFullDisplayMeasurementOnSpan(client.event!);
+  });
+
   test('second call is ignored', async () => {
     startSpanManual(
       {