Anchor the Playwright login helper on the health heading

The greeting it waited for was removed from Home in 449a147.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SKL7sUgNWhukDEz95vSMQv

frontend/tests/utils/user.ts

@@ -7,7 +7,7 @@ export async function logInUser(page: Page, email: string, password: string) {
   await page.getByTestId("password-input").fill(password)
   await page.getByRole("button", { name: "Log In" }).click()
   await page.waitForURL("/")
-  // The greeting is the one part of the dashboard that is there whether or not
-  // any flows are.
-  await expect(page.getByRole("heading", { name: /^Hi, / })).toBeVisible()
+  // The health heading is the one part of the dashboard that is there whether
+  // or not any flows are.
+  await expect(page.getByRole("heading", { name: "Health" })).toBeVisible()
 }