fix(map): 国宝海外回归按钮支持退出激活的回归路线

激活回归路线后再次点击该按钮可直接退出，不再反复弹出文物选择框；
按钮文案在「N 件 / 退出」间切换。

apps/web/src/app/map/page.tsx

@@ -705,7 +705,11 @@ export default function MapPage() {
                   </button>
                 ))}
               <button
-                onClick={() => setShowRepatriationPicker(true)}
+                onClick={() =>
+                  activeRoute?.type === "repatriation"
+                    ? setActiveRoute(null)
+                    : setShowRepatriationPicker(true)
+                }
                 className={`flex w-full items-center justify-between rounded-lg border px-3 py-2 text-xs transition ${
                   activeRoute?.type === "repatriation"
                     ? "border-[#3f9e6a]/55 bg-[#3f9e6a]/16 text-[#aef0c6]"
@@ -716,7 +720,9 @@ export default function MapPage() {
                   <Undo2 size={14} /> 国宝海外回归
                 </span>
                 <span className="text-[10px] text-[#8f8066]">
-                  {routes.filter((r) => r.type === "repatriation").length} 件
+                  {activeRoute?.type === "repatriation"
+                    ? "退出"
+                    : `${routes.filter((r) => r.type === "repatriation").length} 件`}
                 </span>
               </button>
               <button