Tests: a 20 s timeout for the slower CI runner

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

vitest.config.ts

@@ -15,5 +15,9 @@ export default defineConfig({
     environment: 'jsdom',
     globals: true,
     setupFiles: ['./src/test/setup.ts'],
+    /* jsdom with ReUI's popovers is slow on a shared CI runner: a test that opens three
+       menus in a row took more than the default 5 s there while taking about one here. */
+    testTimeout: 20000,
+    hookTimeout: 20000,
   },
 })