test(frontend): add real-auth Playwright e2e suite

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/playwright.config.ts

@@ -1,6 +1,31 @@
 import { defineConfig } from '@playwright/test';
 
+// e2e runs against the dev server (vite :5173), which proxies /api to a backend
+// instance pointed at the isolated `loft_test` database (see .env.test).
 export default defineConfig({
-	webServer: { command: 'npm run build && npm run preview', port: 4173 },
-	testMatch: '**/*.e2e.{ts,js}'
+    testDir: './e2e',
+    testMatch: '**/*.e2e.{ts,js}',
+    fullyParallel: false,
+    workers: 1,
+    use: {
+        baseURL: 'http://localhost:5173',
+        trace: 'on-first-retry'
+    },
+    webServer: [
+        {
+            // backend on :3000, pointed at the test DB via .env.test
+            command: 'cd ../backend && set -a && . ./.env.test && set +a && cargo run',
+            url: 'http://localhost:3000/health',
+            reuseExistingServer: true,
+            timeout: 180_000,
+            stdout: 'pipe',
+            stderr: 'pipe'
+        },
+        {
+            command: 'pnpm dev',
+            url: 'http://localhost:5173',
+            reuseExistingServer: true,
+            timeout: 60_000
+        }
+    ]
 });