Fix typo, store Diagnostics state as local propert ylist file

Trio/Sources/Modules/Onboarding/OnboardingStateModel.swift

@@ -17,7 +17,7 @@ extension Onboarding {
 
         // MARK: - App Diagnostics
 
-        var diagnostisSharingOption: DiagnostisSharingOption = .enabled
+        var diagnosticsSharingOption: DiagnostisSharingOption = .enabled
 
         // MARK: - Nightscout Setup
 
@@ -383,6 +383,7 @@ extension Onboarding {
 
         /// Persists all onboarding data by applying settings and saving therapy values.
         func saveOnboardingData() {
+            applyDiagnostics()
             applyToSettings()
             applyToPreferences()
             applyToPumpSettings()
@@ -392,6 +393,12 @@ extension Onboarding {
             saveISFValues()
         }
 
+        /// Persists the current diagnostics sharing option to a local property list file.
+        func applyDiagnostics() {
+            @PersistedProperty(key: "DiagnosticsSharingState") var storedDiagnosticsOption: String?
+            storedDiagnosticsOption = diagnosticsSharingOption.rawValue
+        }
+
         /// Applies the selected glucose units to the app's settings.
         func applyToSettings() {
             var settingsCopy = settingsManager.settings

Trio/Sources/Modules/Onboarding/View/OnboardingSteps/DiagnosticsStepView.swift

@@ -10,11 +10,11 @@ struct DiagnosticsStepView: View {
 
             ForEach(DiagnostisSharingOption.allCases, id: \.self) { option in
                 Button(action: {
-                    state.diagnostisSharingOption = option
+                    state.diagnosticsSharingOption = option
                 }) {
                     HStack {
-                        Image(systemName: state.diagnostisSharingOption == option ? "largecircle.fill.circle" : "circle")
-                            .foregroundColor(state.diagnostisSharingOption == option ? .accentColor : .secondary)
+                        Image(systemName: state.diagnosticsSharingOption == option ? "largecircle.fill.circle" : "circle")
+                            .foregroundColor(state.diagnosticsSharingOption == option ? .accentColor : .secondary)
                             .imageScale(.large)
 
                         Text(option.displayName)