Stabilize E2E server and retain failure diagnostics

apps/web/playwright.config.ts

@@ -3,7 +3,12 @@ import { defineConfig, devices } from '@playwright/test';
 export default defineConfig({
   testDir: './e2e',
   timeout: 30_000,
-  use: { baseURL: 'http://127.0.0.1:4173', ...devices['Desktop Chrome'] },
+  use: {
+    baseURL: 'http://127.0.0.1:4173',
+    ...devices['Desktop Chrome'],
+    trace: 'retain-on-failure',
+    screenshot: 'only-on-failure',
+  },
   webServer: {
     command: 'pnpm exec vite --port 4173 --strictPort',
     url: 'http://127.0.0.1:4173',

apps/web/vite.config.ts

@@ -8,6 +8,9 @@ export default defineConfig({
     target: 'es2022',
   },
   server: {
+    // E2E installs a stateful fake API in the page. A dev-server reload would
+    // discard it in the middle of a scenario (including other parallel workers).
+    hmr: process.env.VITE_E2E === '1' ? false : undefined,
     host: '127.0.0.1',
     port: 5173,
     strictPort: true,