fix: 修复历史记录点击重复显示问题

- 重构 conversationHelper.ts 中的 selectConversation 函数
- 消除全局 segments 状态导致的消息重复累积
- 为每个 AI 消息单独处理 segments，避免跨消息影响
- 简化消息处理逻辑，提高代码可读性

src/panels/helpers/conversationHelper.ts

@@ -90,21 +90,12 @@ export async function selectConversation(
 
     panel.webview.postMessage({ command: "clearChat" });
 
-    const segments: any[] = [];
     let i = 0;
 
     while (i < taskSession.messages.length) {
       const message = taskSession.messages[i];
 
       if (message.type === MessageType.USER) {
-        if (segments.length > 0) {
-          panel.webview.postMessage({
-            command: "receiveSegments",
-            segments: [...segments],
-          });
-          segments.length = 0;
-        }
-
         const textContent = message.contents?.find((c) => c.type === "TEXT");
         if (textContent && "text" in textContent) {
           panel.webview.postMessage({
@@ -115,12 +106,15 @@ export async function selectConversation(
         i++;
       } else if (message.type === MessageType.AI) {
         if (message.segments && message.segments.length > 0) {
+          // 直接发送 segments
           panel.webview.postMessage({
             command: "receiveSegments",
             segments: message.segments,
           });
-          i++;
         } else {
+          // 构建当前 AI 消息的 segments 并发送
+          const segments: any[] = [];
+
           if (message.text) {
             segments.push({ type: "text", content: message.text });
           }
@@ -138,7 +132,7 @@ export async function selectConversation(
                   nextMsg.id === toolReq.id
                 ) {
                   toolResult = nextMsg.text;
-                  i++;
+                  i++; // 跳过工具执行结果消息
                 }
               }
 
@@ -151,64 +145,26 @@ export async function selectConversation(
             }
           }
 
-          i++;
-
-          while (i < taskSession.messages.length) {
-            const nextMsg = taskSession.messages[i];
-            if (nextMsg.type === MessageType.USER) {
-              break;
-            }
-            if (nextMsg.type === MessageType.AI) {
-              if (nextMsg.segments && nextMsg.segments.length > 0) {
-                break;
-              }
-              if (nextMsg.text) {
-                segments.push({ type: "text", content: nextMsg.text });
-              }
-              if (
-                nextMsg.toolExecutionRequests &&
-                nextMsg.toolExecutionRequests.length > 0
-              ) {
-                for (const toolReq of nextMsg.toolExecutionRequests) {
-                  let toolResult = "";
-                  if (i + 1 < taskSession.messages.length) {
-                    const resultMsg = taskSession.messages[i + 1];
-                    if (
-                      resultMsg.type === MessageType.TOOL_EXECUTION_RESULT &&
-                      resultMsg.id === toolReq.id
-                    ) {
-                      toolResult = resultMsg.text;
-                      i++;
-                    }
-                  }
-                  segments.push({
-                    type: "tool",
-                    toolName: toolReq.name,
-                    askId: toolReq.id,
-                    toolResult: toolResult,
-                  });
-                }
-              }
-              i++;
-            } else if (nextMsg.type === MessageType.TOOL_EXECUTION_RESULT) {
-              i++;
-            } else {
-              i++;
-            }
+          if (segments.length > 0) {
+            panel.webview.postMessage({
+              command: "receiveSegments",
+              segments: segments,
+            });
           }
         }
-      } else {
         i++;
+      } else {
+        // 处理其他类型的消息（如 SYSTEM, TOOL_EXECUTION_RESULT 等）
+        if (message.type === MessageType.TOOL_EXECUTION_RESULT) {
+          // 工具执行结果已经在上面的 AI 消息处理中被处理了，这里跳过
+          i++;
+        } else {
+          // 其他类型消息，如 SYSTEM
+          i++;
+        }
       }
     }
 
-    if (segments.length > 0) {
-      panel.webview.postMessage({
-        command: "receiveSegments",
-        segments: segments,
-      });
-    }
-
     // 发送任务完成消息（历史记录）
     panel.webview.postMessage({
       command: "taskCompleteHistory",