fix: interrupt message speech on confirmation

backend/services/brains/workflow_brain.py

@@ -19,6 +19,7 @@ from pipecat.flows import (
     NodeConfig,
 )
 from pipecat.frames.frames import (
+    InterruptionFrame,
     LLMRunFrame,
     LLMUpdateSettingsFrame,
     OutputTransportMessageUrgentFrame,
@@ -1084,6 +1085,14 @@ class WorkflowBrain(BaseBrain):
             ),
         )
         if result.succeeded:
+            if (
+                completion_policy == MESSAGE_CONFIRMATION
+                and result.action == "confirmed"
+            ):
+                # The client-tool result closes the confirmation gate, while
+                # InterruptionFrame closes any speech still owned by this
+                # Message before the next node can enqueue new output.
+                await runtime.queue_frame(InterruptionFrame())
             await self._emit_trace(
                 "message_completed",
                 nodeId=node_id,