Fix wheel picker crash caused by UIKit/SwiftUI race condition

The crash occurred when UIKit's didSelectRow callback fired during
SwiftUI view teardown, causing an array index out of bounds error.

Fixes:
- Use Identifiable struct for stable ForEach identity
- Hide picker before dismissing to prevent race condition
- Add .id() modifier for stable picker identity
- Disable interactive dismiss to prevent mid-scroll dismissal
- Add small delay before dismiss callbacks

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

iosApp/iosApp/Profile/NotificationPreferencesView.swift

@@ -552,8 +552,7 @@ struct NotificationTimePickerRow: View {
                 },
                 onCancel: {
                     showingTimePicker = false
-                },
-                formatHour: formatHour
+                }
             )
         }
     }
@@ -563,18 +562,37 @@ struct NotificationTimePickerRow: View {
 
 struct TimePickerSheet: View {
     @State private var selectedHour: Int
+    @State private var isPresented: Bool = true
     let onSave: (Int) -> Void
     let onCancel: () -> Void
-    let formatHour: (Int) -> String
 
-    // Pre-computed hours array to avoid range issues with wheel picker
-    private let hours: [Int] = Array(0..<24)
+    // Pre-computed hour labels as a simple struct for stable identity
+    private struct HourOption: Identifiable {
+        let id: Int
+        let label: String
 
-    init(selectedHour: Int, onSave: @escaping (Int) -> Void, onCancel: @escaping () -> Void, formatHour: @escaping (Int) -> String) {
+        var hour: Int { id }
+    }
+
+    private static let hourOptions: [HourOption] = (0..<24).map { hour in
+        let label: String
+        switch hour {
+        case 0: label = "12:00 AM"
+        case 1...11: label = "\(hour):00 AM"
+        case 12: label = "12:00 PM"
+        default: label = "\(hour - 12):00 PM"
+        }
+        return HourOption(id: hour, label: label)
+    }
+
+    init(selectedHour: Int, onSave: @escaping (Int) -> Void, onCancel: @escaping () -> Void) {
         _selectedHour = State(initialValue: selectedHour)
         self.onSave = onSave
         self.onCancel = onCancel
-        self.formatHour = formatHour
+    }
+
+    private func formatHour(_ hour: Int) -> String {
+        Self.hourOptions.first { $0.hour == hour }?.label ?? "\(hour):00"
     }
 
     var body: some View {
@@ -585,14 +603,17 @@ struct TimePickerSheet: View {
                     .foregroundColor(Color.appTextPrimary)
                     .padding(.top)
 
-                Picker("Hour", selection: $selectedHour) {
-                    ForEach(hours, id: \.self) { hour in
-                        Text(formatHour(hour))
-                            .tag(hour)
+                if isPresented {
+                    Picker("Hour", selection: $selectedHour) {
+                        ForEach(Self.hourOptions) { option in
+                            Text(option.label)
+                                .tag(option.hour)
+                        }
                     }
+                    .pickerStyle(.wheel)
+                    .frame(height: 150)
+                    .id("hourPicker") // Stable identity to prevent view recycling issues
                 }
-                .pickerStyle(.wheel)
-                .frame(height: 150)
 
                 Text("Notifications will be sent at \(formatHour(selectedHour)) in your local timezone")
                     .font(.caption)
@@ -609,13 +630,21 @@ struct TimePickerSheet: View {
             .toolbar {
                 ToolbarItem(placement: .cancellationAction) {
                     Button("Cancel") {
-                        onCancel()
+                        // Hide picker before dismissing to prevent race condition
+                        isPresented = false
+                        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                            onCancel()
+                        }
                     }
                     .foregroundColor(Color.appTextSecondary)
                 }
                 ToolbarItem(placement: .confirmationAction) {
                     Button("Save") {
-                        onSave(selectedHour)
+                        // Hide picker before dismissing to prevent race condition
+                        isPresented = false
+                        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                            onSave(selectedHour)
+                        }
                     }
                     .foregroundColor(Color.appPrimary)
                     .fontWeight(.semibold)
@@ -623,6 +652,7 @@ struct TimePickerSheet: View {
             }
         }
         .presentationDetents([.medium])
+        .interactiveDismissDisabled() // Prevent swipe-to-dismiss which can cause race condition
     }
 }