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/textarea.tsx

@@ -1,55 +1,34 @@
-import * as React from "react"
-import { cn } from "@/lib/utils"
+import * as React from 'react';
+import { cn } from '@/lib/utils';
 
-export interface TextareaProps extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {
-  label?: string
-  error?: string
-  'data-testid'?: string
-}
-
-const Textarea = React.forwardRef<HTMLTextAreaElement, TextareaProps>(
-  ({ className, label, error, id, ...props }, ref) => {
-    const generatedId = React.useId()
-    const textareaId = id || generatedId
-    const errorId = `${textareaId}-error`
-    
+/**
+ * 标准 shadcn/ui Textarea 组件
+ * 遵循 shadcn/ui 规范：纯 textarea 元素 + data-slot + cn 工具
+ *
+ * 若需 label/error 属性，请使用 LabeledTextarea 组件
+ */
+const Textarea = React.forwardRef<HTMLTextAreaElement, React.ComponentProps<'textarea'>>(
+  ({ className, ...props }, ref) => {
     return (
-      <div className="w-full">
-        {label && (
-          <label
-            htmlFor={textareaId}
-            className="block text-sm font-medium text-[var(--color-text-secondary)] mb-2"
-          >
-            {label}
-            {props.required && <span className="text-[var(--color-brand-primary)] ml-1">*</span>}
-          </label>
+      <textarea
+        data-slot="textarea"
+        ref={ref}
+        className={cn(
+          'placeholder:text-text-hint selection:bg-brand selection:text-white',
+          'flex min-h-[80px] w-full rounded-md border border-border-primary bg-bg-primary px-3 py-2 text-base',
+          'transition-all duration-fast outline-none',
+          'disabled:cursor-not-allowed disabled:opacity-50',
+          'md:text-sm',
+          'focus-visible:border-brand focus-visible:ring-2 focus-visible:ring-brand/30',
+          'hover:border-border-secondary',
+          'touch-manipulation resize-y',
+          className
         )}
-        <textarea
-          id={textareaId}
-          data-slot="textarea"
-          data-testid={props['data-testid']}
-          className={cn(
-            "placeholder:text-[var(--color-text-hint)] selection:bg-[var(--color-primary)] selection:text-white min-h-[140px] w-full rounded-lg border border-[var(--color-border-primary)] bg-[var(--color-bg-section)] px-4 py-3 text-base text-[var(--color-text-primary)] shadow-sm transition-all duration-300 outline-none disabled:cursor-not-allowed disabled:opacity-50 md:min-h-[80px] md:text-sm md:py-2 resize-none",
-            "focus-visible:border-[var(--color-primary)] focus-visible:ring-2 focus-visible:ring-[var(--color-primary)]/50 focus-visible:shadow-lg focus-visible:shadow-[var(--color-primary)]/20",
-            "hover:border-[var(--color-text-secondary)]",
-            error && "border-[var(--color-brand-primary)] focus-visible:border-[var(--color-brand-primary)] focus-visible:ring-[var(--color-brand-primary)]/50",
-            className
-          )}
-          ref={ref}
-          aria-required={props.required ? "true" : undefined}
-          aria-invalid={error ? "true" : "false"}
-          aria-describedby={error ? errorId : undefined}
-          {...props}
-        />
-        {error && (
-          <p id={errorId} className="mt-1 text-sm text-[var(--color-brand-primary)]" role="alert">
-            {error}
-          </p>
-        )}
-      </div>
-    )
+        {...props}
+      />
+    );
   }
-)
-Textarea.displayName = "Textarea"
+);
+Textarea.displayName = 'Textarea';
 
-export { Textarea }
+export { Textarea };