feat(ui): 重构核心 UI 组件库，新增 shadcn/ui 组件

- 重构 Button、Card、Badge、Input、Textarea 等基础组件
- 新增 Accordion、Alert、Dialog、Dropdown、Form 等 shadcn/ui 组件
- 新增 AnimatedCounter、StatsShowcase、MetricCard 等数据展示组件
- 新增 ScrollReveal 滚动动画组件
- 重构 Toast 通知系统与 Tooltip 提示组件
- 更新设计令牌系统，对齐新品牌视觉

src/components/ui/radio-group.tsx

@@ -0,0 +1,52 @@
+'use client';
+
+import * as React from 'react';
+import * as RadioGroupPrimitive from '@radix-ui/react-radio-group';
+import { Circle } from 'lucide-react';
+import { cn } from '@/lib/utils';
+
+/**
+ * 标准 shadcn/ui RadioGroup 组件
+ * 基于 @radix-ui/react-radio-group
+ */
+const RadioGroup = React.forwardRef<
+  React.ElementRef<typeof RadioGroupPrimitive.Root>,
+  React.ComponentPropsWithoutRef<typeof RadioGroupPrimitive.Root>
+>(({ className, ...props }, ref) => (
+  <RadioGroupPrimitive.Root
+    ref={ref}
+    data-slot="radio-group"
+    className={cn('grid gap-2', className)}
+    {...props}
+  />
+));
+RadioGroup.displayName = RadioGroupPrimitive.Root.displayName;
+
+const RadioGroupItem = React.forwardRef<
+  React.ElementRef<typeof RadioGroupPrimitive.Item>,
+  React.ComponentPropsWithoutRef<typeof RadioGroupPrimitive.Item>
+>(({ className, ...props }, ref) => (
+  <RadioGroupPrimitive.Item
+    ref={ref}
+    data-slot="radio-group-item"
+    className={cn(
+      'aspect-square size-4 rounded-full border border-border-primary bg-bg-primary text-brand shadow-sm',
+      'focus:outline-none focus-visible:ring-2 focus-visible:ring-brand focus-visible:ring-offset-2',
+      'disabled:cursor-not-allowed disabled:opacity-50',
+      'data-[state=checked]:border-brand',
+      'transition-colors duration-fast',
+      className
+    )}
+    {...props}
+  >
+    <RadioGroupPrimitive.Indicator
+      data-slot="radio-group-indicator"
+      className="flex items-center justify-center"
+    >
+      <Circle className="size-2.5 fill-brand text-brand" />
+    </RadioGroupPrimitive.Indicator>
+  </RadioGroupPrimitive.Item>
+));
+RadioGroupItem.displayName = RadioGroupPrimitive.Item.displayName;
+
+export { RadioGroup, RadioGroupItem };