feat(web): Playwright E2E test suite for critical paths (#152)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/web/e2e/navigation.spec.ts

@@ -0,0 +1,86 @@
+import { test, expect } from '@playwright/test';
+import { loginAs, TEST_USER } from './helpers/auth.js';
+
+test.describe('Sidebar navigation', () => {
+  test.beforeEach(async ({ page }) => {
+    await loginAs(page, TEST_USER.email, TEST_USER.password);
+    const url = page.url();
+    test.skip(!url.includes('/chat'), 'No seeded test user — skipping authenticated tests');
+  });
+
+  test('sidebar shows Mosaic brand link', async ({ page }) => {
+    await page.goto('/chat');
+    await expect(page.getByRole('link', { name: /mosaic/i }).first()).toBeVisible();
+  });
+
+  test('Chat nav link navigates to /chat', async ({ page }) => {
+    await page.goto('/settings');
+    await page
+      .getByRole('link', { name: /^chat$/i })
+      .first()
+      .click();
+    await expect(page).toHaveURL(/\/chat/);
+  });
+
+  test('Projects nav link navigates to /projects', async ({ page }) => {
+    await page.goto('/chat');
+    await page
+      .getByRole('link', { name: /projects/i })
+      .first()
+      .click();
+    await expect(page).toHaveURL(/\/projects/);
+  });
+
+  test('Settings nav link navigates to /settings', async ({ page }) => {
+    await page.goto('/chat');
+    await page
+      .getByRole('link', { name: /settings/i })
+      .first()
+      .click();
+    await expect(page).toHaveURL(/\/settings/);
+  });
+
+  test('Tasks nav link navigates to /tasks', async ({ page }) => {
+    await page.goto('/chat');
+    await page.getByRole('link', { name: /tasks/i }).first().click();
+    await expect(page).toHaveURL(/\/tasks/);
+  });
+
+  test('active link is visually highlighted', async ({ page }) => {
+    await page.goto('/chat');
+    // The active link should have a distinct class — check that the Chat link
+    // has the active style class (bg-blue-600/20 text-blue-400)
+    const chatLink = page.getByRole('link', { name: /^chat$/i }).first();
+    const cls = await chatLink.getAttribute('class');
+    expect(cls).toContain('blue');
+  });
+});
+
+test.describe('Route transitions', () => {
+  test.beforeEach(async ({ page }) => {
+    await loginAs(page, TEST_USER.email, TEST_USER.password);
+    const url = page.url();
+    test.skip(!url.includes('/chat'), 'No seeded test user — skipping authenticated tests');
+  });
+
+  test('navigating chat → projects → settings → chat works without errors', async ({ page }) => {
+    await page.goto('/chat');
+    await expect(page).toHaveURL(/\/chat/);
+
+    await page.goto('/projects');
+    await expect(page.getByRole('heading', { name: /projects/i })).toBeVisible();
+
+    await page.goto('/settings');
+    await expect(page.getByRole('heading', { name: /settings/i })).toBeVisible();
+
+    await page.goto('/chat');
+    await expect(page).toHaveURL(/\/chat/);
+  });
+
+  test('back-button navigation works between pages', async ({ page }) => {
+    await page.goto('/chat');
+    await page.goto('/projects');
+    await page.goBack();
+    await expect(page).toHaveURL(/\/chat/);
+  });
+});