fix: 历史回合误显示活跃状态与流式段间隐形空白

apps/desktop/src/renderer/src/components/ChatView.tsx

@@ -48,13 +48,17 @@ function renderTurns(
     if (message.role === 'assistant') {
       let j = i + 1
       while (j < messages.length && messages[j].role === 'assistant') j += 1
+      // turnActive/streaming 是会话级信号：只有延伸到消息列表末尾的最后一个
+      // assistant 组是「活跃回合」。透传给历史回合会让它们误显示
+      // 「已工作/处理中」并保持过程区展开。
+      const isLive = j === messages.length
       items.push(
         <AssistantTurn
           key={`${message.key}-turn`}
           messages={messages.slice(i, j)}
           tools={tools}
-          streaming={streaming}
-          turnActive={turnActive}
+          streaming={streaming && isLive}
+          turnActive={turnActive && isLive}
           pendingApprovals={pendingApprovals}
         />
       )
@@ -65,8 +69,8 @@ function renderTurns(
           key={message.key}
           message={message}
           tools={tools}
-          streaming={streaming}
-          turnActive={turnActive}
+          streaming={streaming && i === messages.length - 1}
+          turnActive={turnActive && i === messages.length - 1}
           pendingApprovals={pendingApprovals}
         />
       )

apps/desktop/src/renderer/src/components/MessageItem.tsx

@@ -177,15 +177,18 @@ export function AssistantTurn({
   const streamNodes: ReactNode[] = []
   let visibleThinkingRows = 0
   if (stream) {
-    stream.segments.forEach((seg, i) => {
+    const segments = stream.segments
+    segments.forEach((seg, i) => {
       if (seg.kind === 'thinking') {
         if (!showStreamThinking) return
         const rows = thinkingRows(seg.text)
         if (rows.length === 0) return
         visibleThinkingRows += rows.length
+        // 该思考段之后已有正文段在流：思考已完成，表头从「思考中…」切回「思考过程」
+        const followedByText = segments.some((s, k) => k > i && s.kind === 'text' && s.text.length > 0)
         streamNodes.push(
           <div key={`seg-${i}`} className="mb-3">
-            <Thinking rows={rows} streaming={streaming} />
+            <Thinking rows={rows} streaming={streaming && !followedByText} />
           </div>
         )
         return

apps/desktop/src/renderer/src/components/StreamingText.tsx

@@ -48,11 +48,10 @@ export function StreamingText({
         />
       </div>
 
-      {/* 操作行：流式结束后淡入 */}
-      <div
-        className="mt-2 flex items-center gap-0.5 transition-opacity duration-[400ms]"
-        style={{ opacity: done ? 1 : 0, pointerEvents: done ? undefined : 'none' }}
-      >
+      {/* 操作行：流式结束后淡入。流式期间不渲染（opacity:0 也会占位，
+        * 每个正文段后会挂一块约 32px 的隐形空白，且完成后卸载造成布局跳动） */}
+      {done && (
+        <div className="mt-2 flex items-center gap-0.5" style={{ animation: 'fade-in 400ms ease both' }}>
           <button
             type="button"
             aria-label={copied ? '已复制' : '复制回答'}
@@ -71,6 +70,7 @@ export function StreamingText({
             )}
           </button>
         </div>
+      )}
 
       {/* Follow-ups：完成后的跟进问题列表 */}
       {done && followUps && followUps.length > 0 && (