fix: increase vitest testTimeout to 10s to prevent flaky App mount test

The "calls getCurrentProject() on mount" test uses vi.resetModules() with
dynamic imports which can be slow. The per-test 10_000ms timeout was not
being respected by vitest, causing it to fail at the 5000ms default.

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

frontend/vitest.config.ts

@@ -9,6 +9,7 @@ export default defineConfig({
   test: {
     environment: "jsdom",
     globals: true,
+    testTimeout: 10_000,
     setupFiles: ["./src/setupTests.ts"],
     css: true,
     exclude: ["tests/e2e/**", "node_modules/**"],