e2e: add medium-priority Playwright coverage (#44)

Co-authored-by: Shaun Campbell <shaun@campbellwireless.net>
Reviewed-on: #44
Co-authored-by: AI Agent <ai-agent@campbellwireless.net>
Co-committed-by: AI Agent <ai-agent@campbellwireless.net>

e2e/helpers/auth.ts

@@ -0,0 +1,27 @@
+import { expect, type Page } from '@playwright/test';
+import { TEST_USERS } from '../setup/test-users.js';
+
+const LOGIN_URL = '/trips/login';
+const DASHBOARD_URL = '/trips/dashboard';
+const PROFILE_URL = '/trips/profile';
+
+export async function loginAsLocalUser(
+	page: Page,
+	username: string,
+	password: string
+): Promise<void> {
+	await page.goto(LOGIN_URL);
+	await page.fill('input[name="identifier"]', username);
+	await page.fill('input[name="password"]', password);
+	await page.click('button[type="submit"]:has-text("Sign in locally")');
+	await page.waitForURL(`**${DASHBOARD_URL}`, { timeout: 15_000 });
+}
+
+export async function ensureSelfProfile(page: Page, email = TEST_USERS.regular.email): Promise<void> {
+	await page.goto(PROFILE_URL);
+	await page.fill('#first_name', 'E2E');
+	await page.fill('#last_name', 'User');
+	await page.fill('#email', email);
+	await page.getByRole('button', { name: 'Save profile' }).click();
+	await expect(page.getByRole('heading', { name: 'My Profile' })).toBeVisible();
+}