fix: 修复SSE连接关闭后停止按钮不消失的问题

- 添加hasCompleted标志位跟踪complete事件
- onClose时检查并补充完成逻辑
- sendMessage时重置hasCompleted状态

src/services/dialogService.ts

@@ -92,6 +92,7 @@ export class DialogSession {
   private toolContext: ToolExecutorContext;
   private accumulatedText = '';
   private isActive = false;
+  private hasCompleted = false;  // 标记是否已收到 complete 事件
   private segments: MessageSegment[] = [];
   private currentTextSegment: MessageSegment | null = null;
 
@@ -331,6 +332,7 @@ export class DialogSession {
     }
 
     this.isActive = true;
+    this.hasCompleted = false;  // 重置完成标志
     this.accumulatedText = '';
     this.segments = [];
     this.currentTextSegment = null;
@@ -686,6 +688,7 @@ export class DialogSession {
 
       onComplete: (data) => {
         this.isActive = false;
+        this.hasCompleted = true;  // 标记已收到 complete 事件
         this.finalizeTextSegment();
 
         // 追踪 AI 消息（用于后端重启后恢复）
@@ -807,6 +810,15 @@ export class DialogSession {
 
       onClose: () => {
         console.log('[DialogSession] SSE 连接已关闭');
+        // 如果没有收到 complete 事件，需要补充完成逻辑
+        if (!this.hasCompleted && this.isActive) {
+          console.log('[DialogSession] 未收到 complete 事件，补充完成处理');
+          this.finalizeTextSegment();
+          if (this.accumulatedText) {
+            historyManager.trackAiMessage(this.accumulatedText);
+          }
+          callbacks.onComplete?.(this.segments);
+        }
         this.isActive = false;
       }
     };