feat(09-03): configure Playwright for E2E testing

- Set testDir to './tests/e2e' for E2E tests
- Configure single worker for database safety
- Add desktop and mobile viewports (Desktop Chrome, Pixel 5)
- Enable screenshots on failure, disable video
- Add webServer to auto-build and preview app
- Create separate docker config for deployment tests

playwright.docker.config.ts

@@ -0,0 +1,25 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * Playwright config for Docker deployment tests
+ * These tests run against the Docker container, not the dev server
+ */
+export default defineConfig({
+	testDir: './tests',
+	testMatch: 'docker-deployment.spec.ts',
+	fullyParallel: true,
+	forbidOnly: !!process.env.CI,
+	retries: process.env.CI ? 2 : 0,
+	workers: process.env.CI ? 1 : undefined,
+	reporter: 'html',
+	use: {
+		baseURL: process.env.BASE_URL || 'http://localhost:3000',
+		trace: 'on-first-retry'
+	},
+	projects: [
+		{
+			name: 'chromium',
+			use: { ...devices['Desktop Chrome'] }
+		}
+	]
+});