Restore focused userspace processor wake coverage

PR #2144 deliberately reduced Guestbook to a minimal React SPA plus Worker and removed its template-coupled processor wake test. Restore that runtime lane as a focused fixture rather than making a sample app special again.

Done when an inline stateful createWorker fixture imports iterate/processors, declares its own zod dependency, and proves a stream append wakes workers.get(ref).processor.wakeStreamProcessor through the deployed Worker Loader. Assert the resulting processor state and the shared zod class identity. Keep the fixture independent of Todo and Guestbook.