Notification tap opens directions to the station

- Alerts (live + real-data test) carry the station name + coordinates in
  userInfo and attach a map snapshot with a red pin, so the expanded
  notification shows where the station is
- Tapping a notification opens Apple Maps driving directions to the
  station from the user's current location (maps:// daddr)
- If Apple Maps hand-off fails (LiveContainer), an in-app map sheet
  (StationMapView) pins the station + user location with a Directions
  button

FuelBoard/ContentView.swift

@@ -159,6 +159,9 @@ struct ContentView: View {
                 showOnboarding = false
             }
         }
+        .sheet(item: $monitor.pendingStationMap) { request in
+            StationMapView(request: request)
+        }
         .onAppear {
             // Onboarding runs first on a fresh install — it owns the initial
             // permission prompts. Location tracking starts once it's done.