ad4f82eb8f
- Introduced the `CollabGuestUiResult` type to distinguish between answers and unavailable states during guest UI requests. - Updated the remote dialog race logic to ignore unavailable guest results and fallback to the local host dialog. - Centralized the `FakeWebSocket` and `InMemoryRelay` test infrastructure into a shared test helpers file. - Cleaned up duplicate mock implementations and updated existing test suites to utilize the shared in-memory relay helpers.