Fix: Segmentation Hide All fails when switching from 2D to 3D fourUp (#5995)

* Fix: Segmentation "Hide All" fails when switching from 2D to 3D four-up viewport

* Update based on the review comment on segmentation load in 3d fourup

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

* fix: simplify the conditional logic

* fix: playwright test

* fix: playwright test

* fix: render timeout in test

---------

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>
Co-authored-by: Belbin-GK <150322972+Belbin-GK@users.noreply.github.com>
Co-authored-by: Devu Jayalekshmi <devu.jayalekshmi@trenser.com>
Co-authored-by: Bill Wallace <wayfarer3130@gmail.com>

extensions/cornerstone/src/services/SyncGroupService/createHydrateSegmentationSynchronizer.ts

@@ -88,12 +88,17 @@ const segmentationRepresentationModifiedCallback = async (
     return;
   }
 
-  // Ensure the segmentation representation aligns with the target viewport type.
-  const type: Enums.SegmentationRepresentations =
-    isVolume3DViewportType(viewport)
-      ? Enums.SegmentationRepresentations.Surface
-      : ((segmentationRepresentationType as Enums.SegmentationRepresentations) ??
-        Enums.SegmentationRepresentations.Labelmap);
+  // Ensure the segmentation representation aligns with the target viewport type
+  const is3D = isVolume3DViewportType(viewport);
+  const requestedRepresentation =
+    segmentationRepresentationType as Enums.SegmentationRepresentations;
+  const { Surface, Labelmap } = Enums.SegmentationRepresentations;
+
+  const type: Enums.SegmentationRepresentations = is3D
+    ? Surface
+    : requestedRepresentation && requestedRepresentation !== Surface
+      ? requestedRepresentation
+      : Labelmap;
 
   await segmentationService.addSegmentationRepresentation(targetViewportId, {
     segmentationId,

tests/SEGHydrationFrom3DFourUp.spec.ts

@@ -60,6 +60,9 @@ test.describe('3D four up SEG hydration', async () => {
 
     // Wait until all viewports have finished rendering
     await viewportRenderCycle;
+    // Hydration propagates labelmap volumes to MPR viewports asynchronously after the
+    // first render cycle resolves.
+    await waitForViewportsRendered(page, { timeout: 240000 });
 
     await checkForScreenshot({
       page,