- Debug section now shows the last device fix (lat/lng to 5dp) and its age.
- In-range indicator uses the SAME criteria as live alerts: stations selling
the monitored fuel within the alert radius of the fix. Green dot + count
when in range, red when none, grey while waiting for a fix.
- Shows the cheapest in-range station (name, distance, price).
- ProximityMonitor recomputes the snapshot on every location/stations
change and on Debug-section appear; ContentView passes the live status.
- SettingsView extracted to its own property to keep TabView body within
the compiler type-check budget. 35 tests pass.