Stabilize E2E server and retain failure diagnostics

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,