test: add authenticated staging smoke helper

apps/ui/playwright.config.js

@@ -1,5 +1,8 @@
 const { defineConfig, devices } = require('@playwright/test');
 
+const baseURL = process.env.PLAYWRIGHT_BASE_URL || 'http://127.0.0.1:3300';
+const skipWebServer = process.env.PLAYWRIGHT_SKIP_WEB_SERVER === '1';
+
 module.exports = defineConfig({
   testDir: './tests/e2e',
   fullyParallel: false,
@@ -13,18 +16,20 @@ module.exports = defineConfig({
     ? [['github'], ['html', { open: 'never' }]]
     : [['list'], ['html', { open: 'never' }]],
   use: {
-    baseURL: process.env.PLAYWRIGHT_BASE_URL || 'http://127.0.0.1:3300',
+    baseURL,
     trace: 'on-first-retry',
     screenshot: 'only-on-failure',
     video: 'retain-on-failure',
   },
-  webServer: {
-    command: 'bash scripts/playwright-stack.sh',
-    cwd: __dirname,
-    url: (process.env.PLAYWRIGHT_BASE_URL || 'http://127.0.0.1:3300') + '/login',
-    timeout: 600_000,
-    reuseExistingServer: false,
-  },
+  webServer: skipWebServer
+    ? undefined
+    : {
+        command: 'bash scripts/playwright-stack.sh',
+        cwd: __dirname,
+        url: `${baseURL}/login`,
+        timeout: 600_000,
+        reuseExistingServer: false,
+      },
   projects: [
     {
       name: 'chromium',