fix: 修复工具下拉框展开/折叠功能

- 修复工具下拉框无法打开的问题，添加正确的图标元素结构
   - 实现状态持久化机制，解决新内容产出时下拉框自动关闭的问题
   - 优化图标显示逻辑，使用 CSS transform 实现平滑旋转动画
   - 折叠状态图标向左旋转 90 度，展开状态图标向下

src/views/messageArea.ts

@@ -410,7 +410,7 @@ export function getMessageAreaStyles(): string {
         display: block;
       }
       .tool-segment-header.collapsed .tool-collapse-icon {
-        transform: rotate(0deg);
+        transform: rotate(-90deg);
       }
       .tool-segment-header:not(.collapsed) .tool-collapse-icon {
         transform: rotate(0deg);
@@ -890,6 +890,9 @@ export function getMessageAreaScript(): string {
       // 存储已回答问题的状态
       const answeredQuestions = new Map(); // askId -> answer
 
+      // 存储工具展开/折叠状态
+      const toolCollapseStates = new Map(); // index -> isCollapsed
+
       // 实时更新分段消息（按后端返回顺序）
       function updateSegmentsRealtime(segments, isComplete) {
         console.log('[WebView] updateSegmentsRealtime 被调用, segments:', segments, 'isComplete:', isComplete);
@@ -921,9 +924,19 @@ export function getMessageAreaScript(): string {
           messagesEl.appendChild(currentSegmentedMessage);
         }
 
+        // 保存当前所有工具的展开/折叠状态
+        if (currentSegmentedMessage) {
+          const toolHeaders = currentSegmentedMessage.querySelectorAll('.tool-segment-header[data-collapsible="true"]');
+          toolHeaders.forEach((header, idx) => {
+            const isCollapsed = header.classList.contains('collapsed');
+            toolCollapseStates.set(idx, isCollapsed);
+          });
+        }
+
         // 清空容器并重新渲染所有段落
         currentSegmentedMessage.innerHTML = '';
 
+        let toolIndex = 0; // 用于跟踪工具段落的索引
         segments.forEach((segment, index) => {
           const segmentDiv = document.createElement('div');
           segmentDiv.className = 'message-segment segment-' + segment.type;
@@ -942,13 +955,19 @@ export function getMessageAreaScript(): string {
             // 检查工具结果是否过长(超过一行显示不下)
             const shouldCollapse = toolResult && toolResult.length > 60;
 
+            // 恢复之前保存的展开/折叠状态
+            const savedState = toolCollapseStates.get(toolIndex);
+            const isCollapsed = savedState !== undefined ? savedState : shouldCollapse;
+            const currentToolIndex = toolIndex;
+            toolIndex++; // 递增工具索引
+
             segmentDiv.innerHTML = \`
-              <div class="tool-segment-header\${shouldCollapse ? ' collapsed' : ''}" data-collapsible="\${shouldCollapse}">
+              <div class="tool-segment-header\${isCollapsed ? ' collapsed' : ''}" data-collapsible="\${shouldCollapse}" data-tool-index="\${currentToolIndex}">
-                \${shouldCollapse ? collapseIconSvg : getToolIcon(segment.toolName)}
+                \${shouldCollapse ? \`<span class="tool-collapse-icon">\${collapseIconSvg}</span>\` : getToolIcon(segment.toolName)}
                 <span class="tool-segment-name">\${getToolDisplayName(segment.toolName) || '工具'}</span>
                 \${toolResult && !shouldCollapse ? \`<span class="tool-segment-result">\${toolResult}</span>\` : ''}
               </div>
-              \${shouldCollapse ? \`<div class="tool-segment-content collapsed"><span class="tool-segment-result" style="display:block;white-space:pre-wrap;max-width:100%;margin-top:8px;margin-left:18px;">\${toolResult}</span></div>\` : ''}
+              \${shouldCollapse ? \`<div class="tool-segment-content\${isCollapsed ? ' collapsed' : ''}" style="max-height:\${isCollapsed ? '0' : 'none'}"><span class="tool-segment-result" style="display:block;white-space:pre-wrap;max-width:100%;margin-top:8px;margin-left:18px;">\${toolResult}</span></div>\` : ''}
             \`;
 
             // 如果是仿真工具且成功完成，尝试添加波形预览
@@ -974,27 +993,24 @@ export function getMessageAreaScript(): string {
               setTimeout(() => {
                 const header = segmentDiv.querySelector('.tool-segment-header');
                 const content = segmentDiv.querySelector('.tool-segment-content');
-                const iconCollapsed = segmentDiv.querySelector('.icon-collapsed');
-                const iconExpanded = segmentDiv.querySelector('.icon-expanded');
 
                 if (header && content) {
                   header.addEventListener('click', function() {
                     const isCollapsed = header.classList.contains('collapsed');
+                    const toolIdx = parseInt(header.getAttribute('data-tool-index') || '0');
 
                     if (isCollapsed) {
                       // 展开
                       header.classList.remove('collapsed');
                       content.classList.remove('collapsed');
                       content.style.maxHeight = content.scrollHeight + 'px';
-                      if (iconCollapsed) iconCollapsed.style.display = 'none';
+                      toolCollapseStates.set(toolIdx, false);
-                      if (iconExpanded) iconExpanded.style.display = 'block';
                     } else {
                       // 折叠
                       header.classList.add('collapsed');
                       content.classList.add('collapsed');
                       content.style.maxHeight = '0';
-                      if (iconCollapsed) iconCollapsed.style.display = 'block';
+                      toolCollapseStates.set(toolIdx, true);
-                      if (iconExpanded) iconExpanded.style.display = 'none';
                     }
                   });
                 }
@@ -1149,7 +1165,7 @@ export function getMessageAreaScript(): string {
 
             segmentDiv.innerHTML = \`
               <div class="tool-segment-header\${shouldCollapse ? ' collapsed' : ''}" data-collapsible="\${shouldCollapse}">
-                \${shouldCollapse ? collapseIconSvg : getToolIcon(segment.toolName)}
+                \${shouldCollapse ? \`<span class="icon-collapsed" style="display:block;width:16px;height:16px;flex-shrink:0;">\${collapseIconSvg}</span><span class="icon-expanded" style="display:none;width:16px;height:16px;flex-shrink:0;">\${collapseIconSvg}</span>\` : getToolIcon(segment.toolName)}
                 <span class="tool-segment-name">\${getToolDisplayName(segment.toolName) || '工具'}</span>
                 \${toolResult && !shouldCollapse ? \`<span class="tool-segment-result">\${toolResult}</span>\` : ''}
               </div>
@@ -1179,27 +1195,24 @@ export function getMessageAreaScript(): string {
               setTimeout(() => {
                 const header = segmentDiv.querySelector('.tool-segment-header');
                 const content = segmentDiv.querySelector('.tool-segment-content');
-                const iconCollapsed = segmentDiv.querySelector('.icon-collapsed');
-                const iconExpanded = segmentDiv.querySelector('.icon-expanded');
 
                 if (header && content) {
                   header.addEventListener('click', function() {
                     const isCollapsed = header.classList.contains('collapsed');
+                    const toolIdx = parseInt(header.getAttribute('data-tool-index') || '0');
 
                     if (isCollapsed) {
                       // 展开
                       header.classList.remove('collapsed');
                       content.classList.remove('collapsed');
                       content.style.maxHeight = content.scrollHeight + 'px';
-                      if (iconCollapsed) iconCollapsed.style.display = 'none';
+                      toolCollapseStates.set(toolIdx, false);
-                      if (iconExpanded) iconExpanded.style.display = 'block';
                     } else {
                       // 折叠
                       header.classList.add('collapsed');
                       content.classList.add('collapsed');
                       content.style.maxHeight = '0';
-                      if (iconCollapsed) iconCollapsed.style.display = 'block';
+                      toolCollapseStates.set(toolIdx, true);
-                      if (iconExpanded) iconExpanded.style.display = 'none';
                     }
                   });
                 }