fix(tracing): Guard getNewScreenTimeToDisplay behind enableTimeToInitialDisplay

NATIVE.getNewScreenTimeToDisplay() was called on every navigation state
change regardless of whether enableTimeToInitialDisplay was enabled.
This native bridge call posts to the main thread and registers a
Choreographer callback (Android) or CADisplayLink (iOS) to capture the
next frame timestamp.

On low-end devices (Fire TV, Chromecast) this is measurable overhead
that the user could not avoid even after setting
enableTimeToInitialDisplay: false.

The dispatch-time native calls (setActiveSpanId, navigationProcessingSpan)
were already correctly guarded behind the flag. This aligns the
state-change-time call with the same guard.

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

Author: antonis

packages/core/src/js/tracing/reactnavigation.ts

@@ -438,7 +438,9 @@ export const reactNavigationIntegration = ({
       return undefined;
     }
 
-    addTimeToInitialDisplayFallback(latestNavigationSpan.spanContext().spanId, NATIVE.getNewScreenTimeToDisplay());
+    if (enableTimeToInitialDisplay) {
+      addTimeToInitialDisplayFallback(latestNavigationSpan.spanContext().spanId, NATIVE.getNewScreenTimeToDisplay());
+    }
 
     if (previousRoute?.key === route.key) {
       debug.log(`[${INTEGRATION_NAME}] Navigation state changed, but route is the same as previous.`);

packages/core/test/tracing/reactnavigation.ttid.test.tsx

@@ -585,6 +585,16 @@ describe('React Navigation - TTID', () => {
         }),
       );
     });
+
+    test('should not call getNewScreenTimeToDisplay when ttid is disabled', () => {
+      jest.runOnlyPendingTimers(); // Flush app start transaction
+
+      mockWrapper.NATIVE.getNewScreenTimeToDisplay.mockClear();
+      mockedNavigation.navigateToNewScreen();
+      jest.runOnlyPendingTimers(); // Flush navigation transaction
+
+      expect(mockWrapper.NATIVE.getNewScreenTimeToDisplay).not.toHaveBeenCalled();
+    });
   });
 
   describe('ttid for preloaded/seen routes', () => {