devops(ci): add testTimeout + hookTimeout to browser vitest config

testTimeout: 30_000 causes Vitest to fail a hanging browser test
within 30 s when Chromium crashes mid-load instead of silently
occupying the CI slot for 14+ min.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/vitest.client-coverage.config.ts

@@ -24,6 +24,8 @@ export default defineConfig({
 		})
 	],
 	test: {
+		testTimeout: 30_000,
+		hookTimeout: 15_000,
 		expect: { requireAssertions: true },
 		browser: {
 			enabled: true,