Road-distance routing previously only fired once a fresh GPS fix arrived via
the location hook/onChange. A returning user on a cold launch waited for that
fix, and if onboarding/flag issues kept tracking from starting, distances
stayed straight-line. Now:
- refreshRoadDistancesIfNeeded() uses the last saved location when the live
fix isn't set yet, so it can run immediately.
- It's called explicitly on launch (already-onboarded branch), on foreground
activation, and on the existing location paths.