add tests for forbidden and not found text

cypress/e2e/userText.cy.js

@@ -55,4 +55,23 @@ describe('The user text detail page', () => {
             expect(response.status).to.eq(403)
         })
     })
+
+    it('non-owner sees forbidden message when viewing another user text', () => {
+        cy.loginAsSecondUser()
+        cy.intercept('GET', '/api/texts/0').as('getText')
+        cy.visit('/texts/0')
+        cy.wait('@getText')
+        cy.get('#text-detail').should(
+            'contain',
+            "You don't have permission to view this text"
+        )
+    })
+
+    it('user sees not found for non-existent text', () => {
+        cy.loginAsUser()
+        cy.intercept('GET', '/api/texts/999').as('getText')
+        cy.visit('/texts/999')
+        cy.wait('@getText')
+        cy.get('#text-detail').should('contain', 'Text not found')
+    })
 })