chore: clean up repo structure

- Add node_modules/, test-results/, e2e-report/, .omp/ to .gitignore
- Remove throwaway debug scripts (debug-pw*.js, debug-login-dom.js)
- Remove empty mock-server/ directory
- Untrack harness artifact (.omp/plans/)
- Add missing project files to git (e2e tests, Dockerfiles, tooling configs)

e2e/drain.spec.ts

@@ -0,0 +1,43 @@
+import { test, expect } from '@playwright/test';
+import { login, resetToAmsterdam } from './utils/auth';
+
+const ZT_PAGE = '/cgi-bin/luci/admin/services/zt-gateway';
+
+test.describe('drain UI', () => {
+  test.beforeEach(async ({ page }) => {
+    await login(page);
+    await resetToAmsterdam(page);
+    await page.goto(ZT_PAGE);
+    await page.waitForSelector('.zt-mode-select');
+  });
+
+  test.afterEach(async ({ page }) => {
+    await resetToAmsterdam(page);
+  });
+
+  test('selecting graceful mode shows drain timeout', async ({ page }) => {
+    await page.locator('.zt-mode-select').selectOption('graceful');
+
+    const timeoutRow = page.locator('.zt-drain-timeout-row');
+    await expect(timeoutRow).toBeVisible();
+  });
+
+  test('switching with graceful mode shows drain panel', async ({ page }) => {
+    // Select tirunelveli radio
+    await page.locator('input[name="zt_gateway_region"][value="tirunelveli"]').check();
+
+    // Change mode to graceful
+    await page.locator('.zt-mode-select').selectOption('graceful');
+
+    // Click "Switch to selected"
+    await page.locator('.cbi-button-positive').click();
+
+    // Wait for the drain panel to appear (may be brief if conntrack is unavailable)
+    const drainPanel = page.locator('.zt-drain-panel');
+    await expect(drainPanel).toBeVisible({ timeout: 45_000 });
+    await expect(drainPanel).toContainText('Graceful drain progress');
+
+    // Panel references old and new IP addresses
+    await expect(drainPanel).toContainText(/\d+\.\d+\.\d+\.\d+/);
+  });
+});