fix(app): display study not found message for all modes (#5752)

* fix(app): move study validation to ModeRoute component

- Moved validation from defaultRouteInit.ts to Mode.tsx
- Added dedicated useEffect hook for study validation

* test: add Playwright test for study not found error page across multiple modes

tests/utils/fixture.ts

@@ -5,6 +5,7 @@ import {
   LeftPanelPageObject,
   RightPanelPageObject,
   ViewportPageObject,
+  NotFoundStudyPageObject,
 } from '../pages';
 
 type PageObjects = {
@@ -13,6 +14,7 @@ type PageObjects = {
   leftPanelPageObject: LeftPanelPageObject;
   rightPanelPageObject: RightPanelPageObject;
   viewportPageObject: ViewportPageObject;
+  notFoundStudyPageObject: NotFoundStudyPageObject;
 };
 
 export const test = base.extend<PageObjects>({
@@ -31,6 +33,9 @@ export const test = base.extend<PageObjects>({
   viewportPageObject: async ({ page }, use) => {
     await use(new ViewportPageObject(page));
   },
+  notFoundStudyPageObject: async ({ page }, use) => {
+    await use(new NotFoundStudyPageObject(page));
+  },
 });
 
 export { expect } from 'playwright-test-coverage';