feat: honour Tap station action on notification and Live Activity taps

Notification body/action taps route through StationTapAction:
Open map opens Apple Maps (existing); More info presents the
in-app detail sheet (falls back to the map sheet when the
station is not in cache).

Live Activity Lock Screen card and island station row pick
their Link destination the same way: Maps URL for Open map,
fuelboard://station deep link for More info, handled in
FuelBoardApp and observed by ContentView.

Also adds the small non-interactive map preview above the
Directions button in the More info sheet.

FuelBoard/WatchSyncManager.swift

@@ -3,6 +3,7 @@ import WatchConnectivity
 
 extension Notification.Name {
     static let fuelBoardWatchRefreshRequested = Notification.Name("FuelBoardWatchRefreshRequested")
+    static let fuelBoardShowStationDetail = Notification.Name("FuelBoardShowStationDetail")
 }
 
 @MainActor