Fix "Hydration Error" (#535)

Fixed a recent "Hydration Error" that was reported (`Hydration failed -
the server rendered HTML didn't match the client.`) that was related to
the cookie snackbar rendering differently between server and client.

Author: AlexJSully

cypress/e2e/landing.cy.ts

@@ -16,4 +16,28 @@ describe('Landing Page', () => {
 		// Check that the profile picture exists on the page
 		cy.get('[data-testid="profile_pic"]').should('exist');
 	});
+
+	it('should show cookie snackbar on first load and not after accepting', () => {
+		const hydrationErrorPattern = /hydration|did not match|content does not match/i;
+		cy.on('window:before:load', (win) => {
+			cy.spy(win.console, 'error').as('consoleError');
+		});
+
+		// The snackbar should be visible on first load
+		cy.get('.MuiSnackbar-root').should('exist').and('be.visible');
+		cy.contains('This website uses cookies to enhance the user experience.').should('be.visible');
+
+		// Click the close button to accept cookies
+		cy.get('.MuiSnackbar-root button[aria-label="close"]').click();
+		cy.get('.MuiSnackbar-root').should('not.exist');
+
+		// Reload the page
+		cy.reload();
+
+		// The snackbar should not appear again
+		cy.get('.MuiSnackbar-root').should('not.exist');
+
+		// Assert no hydration errors in the browser console
+		cy.get('@consoleError').should('not.have.been.calledWithMatch', hydrationErrorPattern);
+	});
 });