fix: chat 视图 loading 在等待首个 assistant 响应期间持续显示

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

@@ -174,7 +174,7 @@
               </view>
             </view>
 
-            <view v-if="generating && generationStatus !== 'failed'" class="chat-loading">
+            <view v-if="showChatLoading" class="chat-loading">
               <view class="loading-orbit" :class="{ streaming: generationStatus === 'streaming' }">
                 <view class="orbit-ring outer"></view>
                 <view class="orbit-ring inner"></view>
@@ -941,6 +941,19 @@ const generationCopy = computed(() => {
   return '正在把你的心愿写成故事'
 })
 
+// chat 视图 loading 显示条件：等待首个 assistant 响应期间
+// - generationPhase === 'generating'：生成流程未完成
+// - generationStatus !== 'failed'：非失败状态
+// - 最后一条消息是 user：说明还没收到 assistant 响应（card/outline/novel）
+const showChatLoading = computed(() => {
+  if (generationPhase.value !== 'generating') return false
+  if (generationStatus.value === 'failed') return false
+  const list = resultMessages.value
+  if (!list || !list.length) return false
+  const lastMsg = list[list.length - 1]
+  return lastMsg && lastMsg.role === 'user'
+})
+
 const generationSubcopy = computed(() => {
   if (generationStatus.value === 'verySlow') return '如果网络波动，稍后会给你温和提示，不会丢掉当前心愿。'
   if (generationStatus.value === 'slow') return 'AI 还没有吐出第一句话，但请求仍在进行中。'