feat: 统一自动化任务调度配置并增强聊天流恢复

apps/lib/features/chat/data/services/ag_ui_service.dart

@@ -187,6 +187,7 @@ class AgUiService {
     String? eventType;
     String? eventId;
     var hasBoundExpectedRun = false;
+    var hasSeenTerminalForRun = false;
     final dataBuffer = StringBuffer();
     final done = Completer<void>();
     late final StreamSubscription<String> subscription;
@@ -257,6 +258,7 @@ class AgUiService {
                   eventThreadId == null || eventThreadId == threadId;
               if (isTerminalEvent &&
                   (isTargetRun || (hasBoundExpectedRun && isThreadMatched))) {
+                hasSeenTerminalForRun = true;
                 stopStream();
                 return;
               }
@@ -291,6 +293,16 @@ class AgUiService {
         stopStream(error: error, stackTrace: stackTrace);
       },
       onDone: () {
+        if (streamToken != _activeStreamToken) {
+          stopStream();
+          return;
+        }
+        if (!hasSeenTerminalForRun) {
+          stopStream(
+            error: StateError('SSE closed before terminal event for run'),
+          );
+          return;
+        }
         stopStream();
       },
       cancelOnError: false,