Introduce unified design tokens and migrate Home, Orders, and Statistics UI.

Establish AppColor/AppFont/AppSpacing/AppRadius theming, shared components, and design-system docs so pilot screens align with Android while keeping iOS-native spacing and touch targets.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/Base/BaseViewController.swift

@@ -13,7 +13,7 @@ class BaseViewController: UIViewController {
 
     override func viewDidLoad() {
         super.viewDidLoad()
-        view.backgroundColor = .systemBackground
+        view.backgroundColor = AppColor.pageBackground
         setupNavigationBar()
         setupUI()
         setupConstraints()
@@ -61,14 +61,14 @@ class BaseViewController: UIViewController {
 
         let container = UIView()
         container.backgroundColor = UIColor.black.withAlphaComponent(0.8)
-        container.layer.cornerRadius = 8
+        container.layer.cornerRadius = AppRadius.sm
         container.clipsToBounds = true
         container.alpha = 0
 
         let label = UILabel()
         label.text = message
         label.textColor = .white
-        label.font = .systemFont(ofSize: 14)
+        label.font = .app(.body)
         label.textAlignment = .center
         label.numberOfLines = 0