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/switch.tsx

@@ -0,0 +1,36 @@
+import { cn } from '@/lib/utils'
+
+export function Switch({
+  checked,
+  onCheckedChange,
+  disabled,
+  className,
+}: {
+  checked: boolean
+  onCheckedChange: (v: boolean) => void
+  disabled?: boolean
+  className?: string
+}) {
+  return (
+    <button
+      type="button"
+      role="switch"
+      aria-checked={checked}
+      disabled={disabled}
+      className={cn(
+        'relative inline-flex h-5 w-9 shrink-0 items-center rounded-full border transition',
+        checked ? 'border-transparent bg-[var(--bg-accent)]' : 'border-[var(--border)] bg-[var(--bg-tertiary)]',
+        disabled && 'opacity-55 cursor-not-allowed',
+        className,
+      )}
+      onClick={() => !disabled && onCheckedChange(!checked)}
+    >
+      <span
+        className={cn(
+          'inline-block h-3.5 w-3.5 rounded-full bg-white shadow transition-transform',
+          checked ? 'translate-x-[18px]' : 'translate-x-[3px]',
+        )}
+      />
+    </button>
+  )
+}