Persist browser authentication state to disk and reuse it across Playwright test runs to skip repeated login flows

Steps

1. Create a dedicated setup script (e.g., `auth.setup.ts`) that logs in once through the full UI, then calls `await page.context().storageState({ path: 'playwright/.auth/user.json' })` to save cookies and localStorage to a file.
2. Add the setup script as a project dependency in `playwright.config.ts` using the `dependencies` field so it runs before other test projects.
3. In the test project that should reuse auth, set `use: { storageState: 'playwright/.auth/user.json' }` — every browser context in that project will be initialised with the saved state.
4. For multi-role setups (admin, regular user), create one setup script and one storage-state file per role, then define separate projects each pointing to the correct file.
5. Add `playwright/.auth/` to `.gitignore` so credentials are never committed to source control.