test(ios): cover context erasure and native capability restrictions

Add Apple-platform tests without presenting them as Linux results. Improve native dark-mode contrast and keep the portable policy suite separate from WebKit tests. Swift formatting and syntax checks pass; Xcode execution remains required.

ios/Sources/ContentView.swift

@@ -10,6 +10,7 @@ struct ContentView: View {
     @State private var settings = false
     @State private var erasing = false
     @Environment(\.scenePhase) private var scenePhase
+    @Environment(\.colorScheme) private var colorScheme
 
     var body: some View {
         NavigationStack {
@@ -75,7 +76,10 @@ struct ContentView: View {
                 }
             }
             .navigationTitle("Yuvomi Mobile").navigationBarTitleDisplayMode(.inline)
-            .tint(Color(red: 108 / 255, green: 58 / 255, blue: 237 / 255))
+            .tint(
+                colorScheme == .dark
+                    ? Color(red: 167 / 255, green: 139 / 255, blue: 250 / 255)
+                    : Color(red: 108 / 255, green: 58 / 255, blue: 237 / 255))
         }
         .task {
             if server == nil, let existing = try? ServerAddress(input) {