Add Playwright e2e coverage and Node 20 pin

frontend/e2e/library-start.spec.ts

@@ -0,0 +1,46 @@
+import { expect, test } from '@playwright/test'
+import {
+  createAuthenticatedApiContext,
+  createTroubleshootingTree,
+  disposeApiContext,
+  uniqueName,
+} from './helpers/api'
+
+test.describe('flow library start-session smoke tests', () => {
+  test('can start a troubleshooting session directly from a search result', async ({ page }) => {
+    const api = await createAuthenticatedApiContext()
+    const tree = await createTroubleshootingTree(api, {
+      name: uniqueName('Playwright Direct Start Flow'),
+      question: 'Did the library launch open the flow?',
+    })
+
+    try {
+      await page.goto('/trees')
+
+      await expect(
+        page.getByRole('heading', { name: 'Flow Library' }),
+      ).toBeVisible()
+
+      await page.getByPlaceholder('Search flows...').fill(tree.name)
+      await page.getByRole('button', { name: 'Search', exact: true }).click()
+
+      const treeCard = page.locator('.bg-card').filter({ hasText: tree.name }).first()
+      await expect(treeCard).toBeVisible()
+      await treeCard.getByRole('button', { name: /^Start(?: Session)?$/ }).click()
+
+      await expect(page).toHaveURL(new RegExp(`/trees/${tree.id}/navigate$`))
+      await expect(page.getByRole('heading', { name: tree.name })).toBeVisible()
+      await expect(page.getByRole('button', { name: 'Start Troubleshooting' })).toBeVisible()
+
+      await page.getByPlaceholder('e.g., INC0012345').fill('PW-DIRECT-START')
+      await page.getByPlaceholder('e.g., Acme Corp').fill('Direct Start Client')
+      await page.getByRole('button', { name: 'Start Troubleshooting' }).click()
+
+      await expect(
+        page.getByRole('heading', { name: 'Did the library launch open the flow?' }),
+      ).toBeVisible()
+    } finally {
+      await disposeApiContext(api)
+    }
+  })
+})