feat(uikit): 新增通用 UI 组件库与主题 token

uikit/src/main/ets/theme/Theme.ets

@@ -0,0 +1,29 @@
+/**
+ * 主题 token：颜色 / 间距 / 字号。
+ * 全 App 统一从这里取值，避免散落魔法值。
+ */
+export class AppColor {
+  static readonly primary: string = '#0A59F7';
+  static readonly primaryPressed: string = '#094CCB';
+  static readonly textPrimary: string = '#182431';
+  static readonly textSecondary: string = '#66182431';
+  static readonly background: string = '#F1F3F5';
+  static readonly white: string = '#FFFFFF';
+  static readonly divider: string = '#0D182431';
+  static readonly danger: string = '#E84026';
+}
+
+export class AppSpacing {
+  static readonly xs: number = 4;
+  static readonly sm: number = 8;
+  static readonly md: number = 16;
+  static readonly lg: number = 24;
+  static readonly xl: number = 32;
+}
+
+export class AppFontSize {
+  static readonly caption: number = 12;
+  static readonly body: number = 14;
+  static readonly title: number = 16;
+  static readonly headline: number = 20;
+}