CarPlay renders Live Activities through the .small activity family
(shared with the Watch Smart Stack), not the lock-screen content view.
Without it, CarPlay fell back to the Dynamic Island's compactLeading/
compactTrailing, which only had the generic "level" SF Symbol and an
empty trailing view — hence the wrong icon and missing text.
Adds .supplementalActivityFamilies([.small]) and a compact layout that
reuses the real LevelBubbleGlyph plus a one-line instruction for that
family, while the lock screen keeps its existing two-line view.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
