🐛(frontend) fix 404 page when reload 403 page

When users were reloading a 403 page, they were
redirected to the 404 page because of Nextjs
routing mechanism. This commit fixes this issue by
removing the 403 page from the pages directory
and creating a component that is used directly
in the layout when a 403 error is detected.

src/frontend/apps/e2e/__tests__/app-impress/utils-share.ts

@@ -1,4 +1,11 @@
-import { Page, expect } from '@playwright/test';
+import { Page, chromium, expect } from '@playwright/test';
+
+import {
+  BROWSERS,
+  BrowserName,
+  keyCloakSignIn,
+  verifyDocName,
+} from './utils-common';
 
 export type Role = 'Administrator' | 'Owner' | 'Member' | 'Editor' | 'Reader';
 export type LinkReach = 'Private' | 'Connected' | 'Public';
@@ -61,6 +68,56 @@ export const updateShareLink = async (
   }
 };
 
+/**
+ * Connects another user to a document.
+ * Useful to test real-time collaboration features.
+ * @param browserName The name of the browser to use.
+ * @param docUrl The URL of the document to connect to.
+ * @param docTitle The title of the document (optional).
+ * @returns An object containing the other browser, context, and page.
+ */
+export const connectOtherUserToDoc = async (
+  browserName: BrowserName,
+  docUrl: string,
+  docTitle?: string,
+) => {
+  const otherBrowserName = BROWSERS.find((b) => b !== browserName);
+  if (!otherBrowserName) {
+    throw new Error('No alternative browser found');
+  }
+
+  const otherBrowser = await chromium.launch({ headless: true });
+  const otherContext = await otherBrowser.newContext({
+    locale: 'en-US',
+    timezoneId: 'Europe/Paris',
+    permissions: [],
+    storageState: {
+      cookies: [],
+      origins: [],
+    },
+  });
+  const otherPage = await otherContext.newPage();
+  await otherPage.goto(docUrl);
+
+  await otherPage.getByRole('button', { name: 'Login' }).click({
+    timeout: 15000,
+  });
+
+  await keyCloakSignIn(otherPage, otherBrowserName, false);
+
+  if (docTitle) {
+    await verifyDocName(otherPage, docTitle);
+  }
+
+  const cleanup = async () => {
+    await otherPage.close();
+    await otherContext.close();
+    await otherBrowser.close();
+  };
+
+  return { otherBrowser, otherContext, otherPage, otherBrowserName, cleanup };
+};
+
 export const mockedInvitations = async (page: Page, json?: object) => {
   let result = [
     {