PaneButton 尺寸类名改用查表

- export/tabs/common/PaneButton.tsx 用 SIZING_CLASS 映射替换 sizing 的嵌套三元

apps/ai-game-creator-shell/src/view/project-development/export/tabs/common/PaneButton.tsx

@@ -18,6 +18,13 @@ const TONE_CLASS: Record<'primary' | 'ghost' | 'brand', string> = {
     'border-[#e2cbb8] bg-white/80 text-[#6f5848] hover:border-[#c7653d] hover:text-[#c7653d]',
 };
 
+/** 尺寸 → 类名，理由同 [`TONE_CLASS`]。 */
+const SIZING_CLASS: Record<'sm' | 'lg' | 'hero', string> = {
+  hero: 'w-full justify-center gap-2 rounded-xl px-6 py-4 text-lg font-bold tracking-wide shadow-md',
+  lg: 'justify-center gap-2 rounded-xl px-6 py-3 text-base font-semibold shadow-sm',
+  sm: 'gap-1.5 rounded-[10px] px-3.5 py-2 text-xs font-semibold',
+};
+
 export function PaneButton({
   children,
   variant = 'ghost',
@@ -38,12 +45,7 @@ export function PaneButton({
   onClick: () => void;
 }) {
   const tone = TONE_CLASS[variant];
-  const sizing =
-    size === 'hero'
-      ? 'w-full justify-center gap-2 rounded-xl px-6 py-4 text-lg font-bold tracking-wide shadow-md'
-      : size === 'lg'
-        ? 'justify-center gap-2 rounded-xl px-6 py-3 text-base font-semibold shadow-sm'
-        : 'gap-1.5 rounded-[10px] px-3.5 py-2 text-xs font-semibold';
+  const sizing = SIZING_CLASS[size];
   return (
     <button
       type="button"