Force dark mode on camera/picker for black safe area bars

- Set overrideUserInterfaceStyle = .dark on UIImagePickerController
- Changes white bars to black (much better looking)
- Camera controls and photo library also appear in dark mode
- Consistent dark appearance regardless of system settings

bitchat/Views/ContentView.swift

@@ -2154,6 +2154,9 @@ struct ImagePickerView: UIViewControllerRepresentable {
         // Use standard full screen - iOS handles safe areas automatically
         picker.modalPresentationStyle = .fullScreen
 
+        // Force dark mode to make safe area bars black instead of white
+        picker.overrideUserInterfaceStyle = .dark
+
         return picker
     }