fix(mini-program): 修复剧本详情页样式和内容显示问题

样式修复:
- 标题添加 flex:1 和 text-overflow: ellipsis，长文本自动省略
- 标题添加左右 margin，避免与返回按钮重叠
- 返回按钮添加 flex-shrink:0 和 z-index，确保不被压缩

内容显示修复:
- 优先读取 script.content 字段（转换后的标准格式）
- 兼容 script.plotJson.fullContent 格式（旧数据）

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

@@ -59,7 +59,10 @@ onMounted(() => {
   // 从 store 获取剧本详情
   if (scriptId) {
     script.value = scripts.value.find(s => s.id === scriptId)
-    if (script.value?.plotJson?.fullContent) {
+    // 优先读取 content 字段（转换后的格式），兼容 plotJson.fullContent
+    if (script.value?.content) {
+      fullContent.value = script.value.content
+    } else if (script.value?.plotJson?.fullContent) {
       fullContent.value = script.value.plotJson.fullContent
     } else {
       fullContent.value = '暂无完整内容'
@@ -90,6 +93,7 @@ const goBack = () => {
   background: rgba(168, 85, 247, 0.1);
   border-bottom: 1px solid rgba(168, 85, 247, 0.2);
   flex-shrink: 0;
+  position: relative;
 }
 
 .header-left {
@@ -100,6 +104,8 @@ const goBack = () => {
   border-radius: 24rpx;
   background: rgba(168, 85, 247, 0.15);
   border: 1px solid rgba(168, 85, 247, 0.2);
+  z-index: 10;
+  flex-shrink: 0;
 }
 
 .back-icon {
@@ -118,6 +124,13 @@ const goBack = () => {
   font-weight: 500;
   color: rgba(243, 232, 255, 0.9);
   font-family: 'Cinzel', 'Inter', serif;
+  flex: 1;
+  text-align: center;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  margin-left: 8rpx;
+  margin-right: 8rpx;
 }
 
 /* ==================== 滚动内容区 ==================== */