test(e2e): add frontend smoke coverage

package.json

@@ -14,6 +14,12 @@
     "test": "jest",
     "test:watch": "jest --watch",
     "test:coverage": "jest --coverage",
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui",
+    "test:e2e:debug": "playwright test --debug",
+    "test:e2e:report": "playwright show-report",
+    "e2e:install": "playwright install chromium",
+    "e2e:serve": "node scripts/startE2eServer.mjs",
     "api:generate": "openapi-typescript contracts/server-v1.openapi.json -o src/generated/serverApi.ts && openapi-typescript contracts/agent-v1.openapi.json -o src/generated/agentApi.ts",
     "api:check": "node scripts/check-api-contracts.mjs",
     "pipeline:trigger": "bash scripts/trigger-gitea-pipeline.sh"
@@ -64,6 +70,7 @@
     "sharp": "0.35.3"
   },
   "devDependencies": {
+    "@playwright/test": "^1.63.0",
     "@svgr/webpack": "^8.1.0",
     "@testing-library/dom": "^10.4.1",
     "@testing-library/jest-dom": "^6.9.1",