center layout: hide sahses initialy until center layout gets activated

fixes #44866

src/vs/workbench/browser/parts/editor/editorGroupsControl.ts

@@ -1049,6 +1049,9 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 			this.centeredEditorSashRight = new Sash(container.getHTMLElement(), this, { baseSize: 5, orientation: Orientation.VERTICAL });
 			registerSashListeners(this.centeredEditorSashLeft);
 			registerSashListeners(this.centeredEditorSashRight);
+			this.centeredEditorSashLeft.hide();
+			console.log('hiding');
+			this.centeredEditorSashRight.hide();
 
 			this.centeredEditorActive = false;
 			this.centeredEditorLeftMarginRatio = 0.5;
@@ -2139,6 +2142,7 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 		const id = this.visibleEditors[Position.ONE] ? this.visibleEditors[Position.ONE].getId() : undefined;
 		const doCentering = this.layoutVertically && this.stacks.groups.length === 1 && this.partService.isEditorLayoutCentered() && id !== PREFERENCES_EDITOR_ID && id !== TEXT_DIFF_EDITOR_ID;
 		if (doCentering && !this.centeredEditorActive) {
+			console.log('showing');
 			this.centeredEditorSashLeft.show();
 			this.centeredEditorSashRight.show();
 
@@ -2147,6 +2151,7 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 				this.resetCenteredEditor(false);
 			}
 		} else if (!doCentering && this.centeredEditorActive) {
+			console.log('hiding');
 			this.centeredEditorSashLeft.hide();
 			this.centeredEditorSashRight.hide();
 		}
@@ -2154,6 +2159,7 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 		this.silos[Position.ONE].setClass('centered', doCentering);
 
 		if (this.centeredEditorActive) {
+			console.log('layouting');
 			this.centeredEditorSashLeft.layout();
 			this.centeredEditorSashRight.layout();
 		}