style(mini-program): 修复剧本生成器核心参数区域布局

- 将叙事风格和故事篇幅选项从 flex-wrap 改为 grid 两列布局
- 与原型图保持一致 (grid-cols-2)

mini-program/src/pages/main/ScriptView.vue

@@ -610,8 +610,8 @@ onMounted(async () => {
 }
 
 .param-options {
-  display: flex;
+  display: grid;
-  flex-wrap: wrap;
+  grid-template-columns: 1fr 1fr;
   gap: 10rpx;
 }