Initial commit: TaskPool React panel

- React frontend with route-level code splitting
- Backend rebranded from Baihu to TaskPool
- DB brand migration script and local compatibility

web/src/components/ui/button.tsx

@@ -0,0 +1,24 @@
+import type { ButtonHTMLAttributes } from 'react'
+import { cn } from '@/lib/utils'
+
+export type ButtonVariant = 'default' | 'secondary' | 'ghost' | 'danger' | 'outline'
+export type ButtonSize = 'sm' | 'md' | 'icon'
+
+export interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: ButtonVariant
+  size?: ButtonSize
+}
+
+export function Button({
+  variant = 'default',
+  size = 'md',
+  className,
+  ...props
+}: ButtonProps) {
+  return (
+    <button
+      className={cn('ui-btn', `ui-btn-${variant}`, `ui-btn-${size}`, className)}
+      {...props}
+    />
+  )
+}