fix(workflow): prevent fixed speech continuation

backend/tests/test_brains.py

@@ -30,6 +30,7 @@ from services.brains.dify_llm import (
     normalize_api_base,
 )
 from services.brains.workflow_brain import ConfiguredFlowManager, WorkflowBrain
+from services.fixed_speech import FIXED_SPEECH_CONTEXT_MARKER
 from services.runtime_variables import prepare_dynamic_config
 from services.action_runtime import ActionOutcome, ActionStatus
 from services.workflow.models import (
@@ -1723,7 +1724,10 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
                 {
                     "id": "agent1",
                     "type": "agent",
-                    "data": {"prompt": "收集基本信息"},
+                    "data": {
+                        "prompt": "收集基本信息",
+                        "entryMode": "generate",
+                    },
                 },
                 {
                     "id": "middle",
@@ -1846,6 +1850,21 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
             if manager.current_node == "agent1":
                 break
         self.assertEqual(manager.current_node, "agent1")
+        self.assertEqual(
+            manager.configs[-1]["task_messages"],
+            [
+                {
+                    "role": "system",
+                    "content": f"{FIXED_SPEECH_CONTEXT_MARKER}\n欢迎使用。",
+                }
+            ],
+        )
+        self.assertFalse(
+            any(
+                message["role"] == "assistant"
+                for message in manager.configs[-1]["task_messages"]
+            )
+        )
 
         # The user-turn processor must return while the second Message is
         # still waiting for its transport playback boundary.
@@ -1868,8 +1887,13 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(
             manager.configs[-1]["task_messages"],
             [
+                {
+                    "role": "system",
+                    "content": (
+                        f"{FIXED_SPEECH_CONTEXT_MARKER}\n现在进入信息确认。"
+                    ),
+                },
                 {"role": "user", "content": "基本信息已经收集完成"},
-                {"role": "assistant", "content": "现在进入信息确认。"},
             ],
         )
 
@@ -2550,7 +2574,14 @@ class WorkflowBrainTests(unittest.IsolatedAsyncioTestCase):
             for frame in worker.frames
             if isinstance(frame, LLMMessagesAppendFrame)
             and frame.messages
-            == [{"role": "assistant", "content": "正在为你结束流程"}]
+            == [
+                {
+                    "role": "system",
+                    "content": (
+                        f"{FIXED_SPEECH_CONTEXT_MARKER}\n正在为你结束流程"
+                    ),
+                }
+            ]
         ]
         self.assertTrue(transition_context_frames)
         transition_events = [