Register IJ-opened dataset as active pyramidal synchronously

Removes the race where OpenResolutionLevelCommand saw no active
pyramidal until the async AWT focus event arrived (flaky under load).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: stefanhahmann

ome-zarr-fiji/src/main/java/ome/zarr/fiji/open/ZarrOpener.java

@@ -156,6 +156,7 @@ public Object openIJWithImage()
 						final PyramidContents< ? > contents = getContents();
 						final PyramidalDataset dataset = new PyramidalDataset( context, contents, preferredResolutionLevel );
 						context.getService( UIService.class ).show( dataset );
+						context.getService( PyramidalService.class ).registerImageJDataset( dataset );
 						logger.info( "Opened dataset in ImageJ: {}", inputUri );
 						return null;
 					},
@@ -191,6 +192,7 @@ public Object openIJWithImage( final int resolutionLevel )
 							throw new NonExistingResolutionLevelException( resolutionLevel, contents.numResolutionLevels() );
 						final PyramidalDataset dataset = new PyramidalDataset( context, contents, resolutionLevel );
 						context.getService( UIService.class ).show( dataset );
+						context.getService( PyramidalService.class ).registerImageJDataset( dataset );
 						logger.info( "Opened dataset at resolution level {} in ImageJ: {}", resolutionLevel, inputUri );
 						return null;
 					},

ome-zarr-fiji/src/main/java/ome/zarr/fiji/plugins/PyramidalService.java

@@ -168,10 +168,25 @@ public void unregisterBdvWindow( final Window window )
 	}
 
 	/** Records {@code dataset} as the active pyramidal, replacing any previously active one. */
-	void notifyBdvWindowFocused( final Pyramidal dataset )
+	void notifyBdvWindowFocused( final Pyramidal pyramidal )
 	{
-		logger.trace( "BDV window focused: {}", dataset );
-		activePyramidal.set( dataset );
+		logger.trace( "BDV window focused: {}", pyramidal );
+		activePyramidal.set( pyramidal );
+		logger.trace( "Active pyramidal set to: {}", activePyramidal.get() );
+	}
+
+	/**
+	 * Records the given {@code pyramidal} as the active pyramidal immediately when it is opened in an
+	 * ImageJ window, without waiting for the asynchronous AWT {@code "activeWindow"} focus
+	 * event to arrive at the new {@link ImageWindow}. This mirrors the synchronous registration
+	 * that {@link #registerBdvWindow} performs for BDV windows. So a freshly opened pyramidal is
+	 * the active pyramidal as soon as the open call returns rather than only once the native
+	 * windowing system delivers focus (which may be delayed or never happen under load).
+	 */
+	public void registerImageJDataset( final Pyramidal pyramidal )
+	{
+		logger.trace( "ImageJ dataset opened: {}", pyramidal );
+		activePyramidal.set( pyramidal );
 		logger.trace( "Active pyramidal set to: {}", activePyramidal.get() );
 	}