Close test-gap noise rows and sync coverage documentation.

Restore P1/P2/fleet/erasure COVERED rows in PROBLEMS.md with refreshed counts; drop fixed poll-duplication and Vitest-noise items. Silence ECONNREFUSED stderr in Vitest setup, alias download mock exports, and expand erasure/Path Tracer test coverage.

server/web/e2e/path-tracer.spec.ts

@@ -0,0 +1,66 @@
+import { expect, test } from '@playwright/test';
+import { loginToDashboard } from './fixtures';
+import { ensureLiveStubAgent, isLiveStubReady } from './live-stub';
+import { E2E_STUB_AGENT_HOSTNAME, E2E_STUB_AGENT_ID } from './stub-agent';
+
+const SESSION_ID = 'e2e-rs-lanes-sess';
+
+test.describe('Path Tracer E2E', () => {
+  test.beforeAll(async ({ request }) => {
+    await ensureLiveStubAgent(request);
+  });
+
+  test.beforeEach(async ({ page }) => {
+    test.skip(
+      !isLiveStubReady(),
+      'Requires live E2E server (test-suite phase 8 on :18989 or AETHERFORGE_URL)',
+    );
+
+    await page.route('**/pathtrace/start', async (route) => {
+      await route.fulfill({
+        json: {
+          session_id: SESSION_ID,
+          hops: [{ agent_id: E2E_STUB_AGENT_ID, status: 'pending' }],
+        },
+      });
+    });
+    await page.route(`**/pathtrace/${SESSION_ID}/status`, async (route) => {
+      await route.fulfill({
+        json: {
+          session_id: SESSION_ID,
+          ready: false,
+          hops: [{ agent_id: E2E_STUB_AGENT_ID, status: 'pending' }],
+          spread_routes: [
+            {
+              target_subnet: '192.168.1.0/24',
+              seed_agent_id: E2E_STUB_AGENT_ID,
+              seed_agent_name: E2E_STUB_AGENT_HOSTNAME,
+              egress_agent_id: E2E_STUB_AGENT_ID,
+              join_lane: 'dns_txt',
+              score: 0.85,
+              erasure_lanes_enabled: true,
+            },
+          ],
+        },
+      });
+    });
+
+    await loginToDashboard(page);
+    await page.goto('/pathtracer');
+    await expect(page.getByRole('heading', { name: /Path Tracer/i })).toBeVisible({
+      timeout: 10_000,
+    });
+  });
+
+  test('shows RS lanes hint on spread routes when erasure is enabled', async ({ page }) => {
+    const card = page.locator('.pt-agent-card').filter({ hasText: E2E_STUB_AGENT_HOSTNAME });
+    await expect(card).toBeVisible({ timeout: 15_000 });
+    await card.click();
+    await page.getByRole('button', { name: /TRACE/i }).click();
+
+    await expect(page.getByText('Spread Routes')).toBeVisible({ timeout: 15_000 });
+    await expect(page.getByText(/192\.168\.1\.0\/24/)).toBeVisible();
+    await expect(page.getByText(/dns_txt/)).toBeVisible();
+    await expect(page.getByText(/RS lanes/)).toBeVisible();
+  });
+});