refactor(chat): 优化加载视图显示逻辑

- 提取加载视图更新逻辑到独立方法 updateLoadingViews
- 根据是否有问题内容决定是否显示加载动画
- 简化条件判断逻辑，提高代码可读性
- 保持滚动到底部功能的一致性调用

app/src/main/java/com/nova/brain/glass/ui/ChatActivity.kt

@@ -35,6 +35,8 @@ class ChatActivity : BaseListFormLayoutNormalActivity<ChatItem, ChatVM, Activity
 
     override fun initData() {
         super.initData()
+        val question = intent.getStringExtra("question") ?: ""
+        val hasQuestion = question.isNotEmpty()
 
         // SSE 流式内容更新时持续滚底
         viewModel.result.observe(this) {
@@ -43,20 +45,26 @@ class ChatActivity : BaseListFormLayoutNormalActivity<ChatItem, ChatVM, Activity
 
         // loading=true：显示旋转进度；loading=false：显示静态占位图
         val isLoading = viewModel.loading.value ?: false
-        binding.loadingProgress.visibility = if (isLoading) View.VISIBLE else View.GONE
-        binding.loadingIdleIcon.visibility = if (isLoading) View.GONE else View.VISIBLE
+        updateLoadingViews(isLoading, hasQuestion)
         viewModel.loading.observe(this) { loading ->
-            binding.loadingProgress.visibility = if (loading) View.VISIBLE else View.GONE
-            binding.loadingIdleIcon.visibility = if (loading) View.GONE else View.VISIBLE
+            updateLoadingViews(loading, hasQuestion)
             recyclerView.post { scrollToBottom() }
         }
-
-        val question = intent.getStringExtra("question") ?: ""
-        if (question.isNotEmpty()) {
+        if (hasQuestion) {
             viewModel.prepareTopic(question)
         }
     }
 
+    private fun updateLoadingViews(loading: Boolean, hasQuestion: Boolean) {
+        if (!hasQuestion) {
+            binding.loadingProgress.visibility = View.GONE
+            binding.loadingIdleIcon.visibility = View.VISIBLE
+            return
+        }
+        binding.loadingProgress.visibility = if (loading) View.VISIBLE else View.GONE
+        binding.loadingIdleIcon.visibility = if (loading) View.GONE else View.VISIBLE
+    }
+
     private fun recognizeAndChat() {
         // 识别由 AsrHelper 在 onFinalResult 中统一触发，此处无需主动发起
     }