Add Fingerbank e2e coverage; fix two test races found along the way

- deep-check.spec.ts: new test asserting a Fingerbank ID + confidence
  label appears (targets the Nintendo device specifically, skips if
  it's not currently on the network -- not something the test suite
  controls). First run false-skipped because it checked row.count()
  before waiting for the device table to actually render.
- device-ratio.spec.ts: badge counts and displayed text were read as
  two separate one-shot queries (.count()/.textContent() don't
  auto-retry like expect() matchers), which raced a background poll
  once and failed. Wrapped the whole comparison in expect().toPass()
  so it retries atomically instead. Confirmed fixed: 4/4 clean runs
  with retries disabled.

15/15 e2e tests green across 8 spec files.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

e2e/tests/deep-check.spec.ts

@@ -30,6 +30,35 @@ test("deep check button runs a check and shows results for an unknown device", a
   await expect(resultRow).not.toBeEmpty();
 });
 
+test("deep check surfaces a Fingerbank identification with a confidence label", async ({ page }) => {
+  test.skip(!PASSWORD, "LOCAL_PASSWORD not set");
+
+  await page.goto("/");
+  await page.getByPlaceholder("Username").fill(USERNAME);
+  await page.getByPlaceholder("Password").fill(PASSWORD);
+  await page.getByRole("button", { name: "Sign in" }).click();
+  // Wait for the table to actually render before checking whether the
+  // target device is in it -- checking row.count() too early always finds
+  // zero rows and skips the test regardless of whether the device is really
+  // on the network. Bit me on the first run of this test.
+  await expect(page.locator(".device-table tbody tr").first()).toBeVisible({ timeout: 15_000 });
+
+  // The Nintendo device (192.168.1.106) reliably gets a Fingerbank match, if
+  // it's still on the network -- skip rather than fail if it's gone, since
+  // this specific IP isn't something the test suite controls.
+  const row = page.locator('tr[data-ip="192.168.1.106"]');
+  test.skip((await row.count()) === 0, "192.168.1.106 not currently on the network");
+
+  await row.getByRole("button", { name: /deep check/i }).click();
+  await expect(page.locator(".deep-check-row").first()).toBeVisible({ timeout: 20_000 });
+
+  const resultText = await page.locator(".deep-check-row").first().textContent();
+  expect(resultText).toContain("Fingerbank ID");
+  // Confidence label should always accompany a score -- never a bare
+  // number, which could be mistaken for a confirmed identification.
+  expect(resultText).toMatch(/low confidence|moderate confidence|high confidence|very high confidence/);
+});
+
 test("known devices have no deep check button", async ({ page }) => {
   test.skip(!PASSWORD, "LOCAL_PASSWORD not set");
 

e2e/tests/device-ratio.spec.ts

@@ -12,12 +12,17 @@ test("known/unknown ratio matches the actual badge counts", async ({ page }) =>
   await page.getByRole("button", { name: "Sign in" }).click();
   await expect(page.locator(".device-table tbody tr").first()).toBeVisible({ timeout: 15_000 });
 
+  // Re-reads badge counts and the displayed text together, retrying the
+  // whole comparison if they're ever caught mid-render (e.g. a background
+  // poll landing between the two reads) instead of a one-shot comparison —
+  // .count() and .textContent() don't auto-wait/retry the way expect()
+  // matchers do, so a bare single read raced a poll and failed once already.
+  await expect(async () => {
     const knownCount = await page.locator(".device-badge.known").count();
     const unknownCount = await page.locator(".device-badge.unknown").count();
-
     const ratioText = await page.locator(".device-ratio").textContent();
-  expect(ratioText).toBe(`${knownCount} known / ${unknownCount} unknown`);
-
     const countText = await page.locator(".device-count").textContent();
+    expect(ratioText).toBe(`${knownCount} known / ${unknownCount} unknown`);
     expect(countText).toBe(`(${knownCount + unknownCount})`);
+  }).toPass({ timeout: 10_000 });
 });