fix: add validate to e2e config

frontend/cypress/support/e2e.ts

@@ -46,7 +46,16 @@ beforeEach(() => {
   // We use a Cypress session to inject inject a Local Storage key
   // so that we can detect when the browser app is running in Cypress.
   // https://docs.cypress.io/faq/questions/using-cypress-faq#How-do-I-preserve-cookies--localStorage-in-between-my-tests
-  cy.session('cypress', () => {
-    window.localStorage.setItem('IS_CYPRESS', 'true')
-  })
+  cy.session(
+    'cypress',
+    () => {
+      window.localStorage.setItem('IS_CYPRESS', 'true')
+    },
+    // https://www.cypress.io/blog/mistake-when-using-cy-session-and-how-to-solve-it
+    {
+      validate() {
+        window.localStorage.getItem('IS_CYPRESS') === 'true'
+      }
+    }
+  )
 })