feat: complete chat sessions and production startup

frontend/playwright.config.ts

@@ -0,0 +1,7 @@
+import { defineConfig } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './tests',
+  use: { baseURL: 'http://127.0.0.1:4173', browserName: 'chromium' },
+  webServer: { command: 'npm run dev -- --host 127.0.0.1 --port 4173', url: 'http://127.0.0.1:4173', reuseExistingServer: false },
+});