feat(mini-program): ScriptDetailView 新增小说消息操作按钮组

- 新增 collapsedMessageIds ref + 5 个函数（isMessageCollapsed、getMessageDisplayContent、toggleMessageCollapse、copyMessageContent、playMessageTts）
- 为 kind === 'novel' 的消息添加折叠/展开、复制、播放按钮
- 添加 .collapse-toggle-row、.message-actions、.action-btn 样式
- H5 验收通过：复制按钮触发 Toast、播放按钮切换 TTS 状态（▶播放 ↔ Ⅱ暂停）、折叠按钮切换文案

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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

@@ -72,7 +72,27 @@
 
           <!-- 小说正文（Markdown 渲染） -->
           <view v-else-if="msg.kind === 'novel'" class="chat-bubble system novel-bubble">
-            <Markdown :content="msg.content" />
+            <Markdown :content="getMessageDisplayContent(msg)" />
+
+            <!-- 折叠/展开按钮（内容超过预览长度时显示） -->
+            <view v-if="msg.content && msg.content.length > ASSISTANT_MESSAGE_PREVIEW_LENGTH" class="collapse-toggle-row" @click="toggleMessageCollapse(msg)">
+              <text class="collapse-toggle-text">{{ isMessageCollapsed(msg) ? '展开全文' : '收起全文' }}</text>
+              <view class="collapse-chevron" :class="{ down: isMessageCollapsed(msg) }">
+                <view></view>
+                <view></view>
+              </view>
+            </view>
+
+            <!-- 操作按钮组 -->
+            <view class="message-actions">
+              <button class="action-btn" @click="copyMessageContent(msg)">
+                <text>复制</text>
+              </button>
+              <button class="action-btn primary" @click="playMessageTts(msg)">
+                <text class="action-icon">{{ ttsPlayer.playing.value ? 'Ⅱ' : '▶' }}</text>
+                <text>{{ ttsPlayer.playing.value ? '暂停' : '播放' }}</text>
+              </button>
+            </view>
           </view>
         </view>
 
@@ -106,10 +126,14 @@ const store = useAppStore()
 const scriptId = ref('')
 const script = ref(null)
 const resultMessages = ref([])
+const collapsedMessageIds = ref({})
 const pagePath = '/pages/main/ScriptDetailView'
 const ttsPlayer = useTtsPlayer({ pagePath })
 const { capsuleTopReservePx, topbarStyle } = useMenuButtonSafeArea({ extraTopPx: 10 })
 
+// 小说正文折叠时的预览长度（字符）
+const ASSISTANT_MESSAGE_PREVIEW_LENGTH = 120
+
 const lengthText = computed(() => {
   const map = { short: '短篇', medium: '中篇', long: '长篇' }
   return map[script.value?.length] || script.value?.length || '中篇'
@@ -125,6 +149,70 @@ const detailTtsIcon = computed(() => {
   return ttsPlayer.playing.value ? 'Ⅱ' : '▶'
 })
 
+/**
+ * 判断消息是否处于折叠状态
+ */
+const isMessageCollapsed = (message) => {
+  return Boolean(collapsedMessageIds.value[message.id])
+}
+
+/**
+ * 获取消息显示内容（折叠时截断到预览长度）
+ */
+const getMessageDisplayContent = (message) => {
+  const content = String(message?.content || '')
+  if (!isMessageCollapsed(message)) return content
+  if (content.length <= ASSISTANT_MESSAGE_PREVIEW_LENGTH) return content
+  return `${content.slice(0, ASSISTANT_MESSAGE_PREVIEW_LENGTH)}...`
+}
+
+/**
+ * 切换消息折叠/展开状态
+ */
+const toggleMessageCollapse = (message) => {
+  collapsedMessageIds.value = {
+    ...collapsedMessageIds.value,
+    [message.id]: !isMessageCollapsed(message)
+  }
+  analytics.track('script_message_collapse_toggle', {
+    message_id: message?.id || '',
+    collapsed: collapsedMessageIds.value[message.id]
+  }, { eventType: 'script', pagePath })
+}
+
+/**
+ * 复制消息内容到剪贴板
+ */
+const copyMessageContent = (message) => {
+  const content = String(message?.content || '')
+  if (!content.trim()) {
+    uni.showToast({ title: '暂无可复制内容', icon: 'none' })
+    return
+  }
+  uni.setClipboardData({
+    data: content,
+    success: () => {
+      uni.showToast({ title: '已复制', icon: 'success' })
+    }
+  })
+  analytics.track('script_message_copy_click', {
+    message_id: message?.id || '',
+    content_length: content.length
+  }, { eventType: 'script', pagePath })
+}
+
+/**
+ * 播放消息 TTS 音频（播放整个剧本的音频）
+ */
+const playMessageTts = (message) => {
+  const scriptIdValue = script.value?.id || ''
+  ttsPlayer.playSource(scriptIdValue)
+  analytics.track('script_message_tts_click', {
+    message_id: message?.id || '',
+    script_id: scriptIdValue
+  }, { eventType: 'script', pagePath })
+}
+
 /**
  * 从后端 message 列表重建统一对话消息流
  * 复刻 ScriptView 生成时的 chat-bubble 展示结构
@@ -522,6 +610,110 @@ onUnmounted(() => {
 .novel-bubble {
   padding: 32rpx;
 }
+
+/* 折叠/展开按钮行 */
+.collapse-toggle-row {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 12rpx;
+  margin-top: 20rpx;
+  padding: 16rpx 0;
+  border-radius: 999rpx;
+  background: rgba(88, 28, 135, 0.12);
+  border: 1rpx solid rgba(192, 132, 252, 0.28);
+  color: rgba(246, 230, 255, 0.96);
+  font-size: 26rpx;
+  font-weight: 700;
+}
+
+.collapse-toggle-row:active {
+  transform: scale(0.98);
+  opacity: 0.92;
+}
+
+.collapse-toggle-text {
+  line-height: 1;
+}
+
+/* 折叠箭头图标 */
+.collapse-chevron {
+  position: relative;
+  width: 20rpx;
+  height: 16rpx;
+  flex-shrink: 0;
+  transition: transform 0.18s ease;
+}
+
+.collapse-chevron.down {
+  transform: rotate(180deg);
+}
+
+.collapse-chevron view {
+  position: absolute;
+  top: 7rpx;
+  width: 12rpx;
+  height: 4rpx;
+  border-radius: 999rpx;
+  background: linear-gradient(90deg, #fff3b0, #ffd86b);
+  box-shadow: 0 0 12rpx rgba(255, 216, 107, 0.5);
+}
+
+.collapse-chevron view:first-child {
+  left: 0;
+  transform: rotate(-38deg);
+  transform-origin: right center;
+}
+
+.collapse-chevron view:last-child {
+  right: 0;
+  transform: rotate(38deg);
+  transform-origin: left center;
+}
+
+/* 操作按钮组 */
+.message-actions {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 14rpx;
+  margin-top: 20rpx;
+}
+
+.action-btn {
+  height: 72rpx;
+  min-height: 72rpx;
+  padding: 0 8rpx;
+  border-radius: 28rpx;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  color: #e8ccff;
+  font-size: 26rpx;
+  font-weight: 700;
+  line-height: 1.15;
+  text-align: center;
+  white-space: normal;
+  box-sizing: border-box;
+  background: rgba(88, 28, 135, 0.18);
+  border: 1rpx solid rgba(192, 132, 252, 0.35);
+}
+
+.action-btn.primary {
+  color: #fff;
+  background: linear-gradient(145deg, #8c44f2, #5f1db8);
+}
+
+.action-icon {
+  margin-right: 8rpx;
+  font-size: 24rpx;
+  font-weight: 900;
+  line-height: 1;
+}
+
+.action-btn::after {
+  border: 0;
+}
+
 .empty-flow {
   padding: 80rpx 0;
   text-align: center;