Align Settings dependent disabled states

FuelBoard/SettingsView.swift

@@ -198,7 +198,7 @@ struct SettingsView: View {
                                 .foregroundStyle(.orange)
                         }
                     }
-                    .disabled(!fuelSavingsSettings.enabled)
+                    .settingsDependencyEnabled(fuelSavingsSettings.enabled)
                 } header: {
                     Text("Fuel Savings")
                 } footer: {
@@ -582,7 +582,7 @@ struct SettingsView: View {
                                 )
                             }
                             .buttonStyle(.plain)
-                            .disabled(tipStore.purchaseInProgress)
+                            .settingsDependencyEnabled(!tipStore.purchaseInProgress)
                         }
                     }
                     .listRowBackground(Color.clear)
@@ -925,6 +925,16 @@ struct SettingsView: View {
     }
 }
 
+/// Applies the native unavailable state to a complete dependent settings group
+/// and also dims non-control content (read-outs, icons and explanatory text),
+/// which does not automatically adopt a disabled appearance from SwiftUI.
+private extension View {
+    func settingsDependencyEnabled(_ isEnabled: Bool) -> some View {
+        disabled(!isEnabled)
+            .opacity(isEnabled ? 1 : 0.65)
+    }
+}
+
 /// Loads the three tip tiers and drives their purchases.
 @MainActor
 final class TipStore: ObservableObject {