Refactor to MVVM architecture

ApplicationLibrary/Views/Setting/SettingViewModel.swift

@@ -0,0 +1,21 @@
+import Library
+import SwiftUI
+
+@MainActor
+final class SettingViewModel: ObservableObject {
+    @Published var isLoading = true
+    @Published var taiwanFlagAvailable = false
+
+    nonisolated func checkTaiwanFlagAvailability() async {
+        let available: Bool
+        if ApplicationLibrary.inPreview {
+            available = true
+        } else {
+            available = !DeviceCensorship.isChinaDevice()
+        }
+        await MainActor.run {
+            taiwanFlagAvailable = available
+            isLoading = false
+        }
+    }
+}