fix(e2e): seed dev user in localStorage to prevent login redirect

E2E tests were failing because the dev login selector redirects to
/login when AUTH_DISABLED=true and no dev user is in localStorage.
Added a shared Playwright fixture that pre-seeds localStorage with
a default dev user before each test.

Also rebased onto latest main to resolve merge conflict in App.test.tsx.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/e2e/tests/book.spec.ts

@@ -1,4 +1,4 @@
-import { test, expect } from "@playwright/test";
+import { test, expect } from "./fixtures.js";
 
 /**
  * Booking portal happy-path E2E test.