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/chat.spec.ts

@@ -0,0 +1,50 @@
+import { test, expect } from '@playwright/test';
+import { loginAs, TEST_USER } from './helpers/auth.js';
+
+test.describe('Chat page', () => {
+  test.beforeEach(async ({ page }) => {
+    await loginAs(page, TEST_USER.email, TEST_USER.password);
+    // If login failed (no seeded user in env) we may be on /login — skip
+    const url = page.url();
+    test.skip(!url.includes('/chat'), 'No seeded test user — skipping authenticated tests');
+  });
+
+  test('chat page loads and shows the welcome message or conversation list', async ({ page }) => {
+    await page.goto('/chat');
+    // Either there are conversations listed or the welcome empty-state is shown
+    const hasWelcome = await page
+      .getByRole('heading', { name: /welcome to mosaic chat/i })
+      .isVisible()
+      .catch(() => false);
+    const hasConversationPanel = await page
+      .locator('[data-testid="conversation-list"], nav, aside')
+      .first()
+      .isVisible()
+      .catch(() => false);
+
+    expect(hasWelcome || hasConversationPanel).toBe(true);
+  });
+
+  test('new conversation button is visible', async ({ page }) => {
+    await page.goto('/chat');
+    // "Start new conversation" button or a "+" button in the sidebar
+    const newConvButton = page.getByRole('button', { name: /new conversation|start new/i }).first();
+    await expect(newConvButton).toBeVisible({ timeout: 10_000 });
+  });
+
+  test('clicking new conversation shows a chat input area', async ({ page }) => {
+    await page.goto('/chat');
+    // Find any button that creates a new conversation
+    const newBtn = page.getByRole('button', { name: /new conversation|start new/i }).first();
+    await newBtn.click();
+    // After creating, a text input for sending messages should appear
+    const chatInput = page.getByRole('textbox').or(page.locator('textarea')).first();
+    await expect(chatInput).toBeVisible({ timeout: 10_000 });
+  });
+
+  test('sidebar navigation is present on chat page', async ({ page }) => {
+    await page.goto('/chat');
+    // The app-shell sidebar should be visible
+    await expect(page.getByRole('link', { name: /chat/i }).first()).toBeVisible();
+  });
+});