ARCH-062 combined two distinct concerns under one heading, causing
the bot to demand CUJ InteractiveBrowserTest for non-UI code like
tab helpers and services. Split into:
- ARCH-062: CUJ tests required only for features with UI changes
- ARCH-062b: Avoid change detector tests (general testing guidance)
Clarify that non-UI components should use unit tests or browser tests
appropriate to the code rather than CUJ tests.