Unify disabled states and preserve station verdicts

FuelBoard/FuelBoardDisabledState.swift

@@ -0,0 +1,12 @@
+import SwiftUI
+
+/// Applies FuelBoard's shared unavailable appearance and native interaction state
+/// to a complete dependent row or group. Apply it once at the highest dependent
+/// container so labels, values, icons, descriptions and controls fade together.
+extension View {
+    func fuelBoardDisabledState(isEnabled: Bool) -> some View {
+        disabled(!isEnabled)
+            .allowsHitTesting(isEnabled)
+            .opacity(isEnabled ? 1 : 0.5)
+    }
+}