One status for challenges and signals

Challenges and signals now show a single, consistent status wherever you see them, running from Initiated through Connected, with the same wording and the same icons at every step.

Before this, the same underlying item could be described one way in one place and another way somewhere else, so status was something you confirmed by asking rather than by reading the screen.

Status badges also render correctly in dark mode, where some of them were previously unreadable.