diff --git a/web/hwlab-cloud-web/src/stores/workbench.ts b/web/hwlab-cloud-web/src/stores/workbench.ts
index 5ce51465..40fd20b0 100644
--- a/web/hwlab-cloud-web/src/stores/workbench.ts
+++ b/web/hwlab-cloud-web/src/stores/workbench.ts
@@ -503,15 +503,24 @@ export const useWorkbenchStore = defineStore("workbench", () => {
   function syncTurnStatusToMessage(traceId: string, result: AgentChatResultResponse | TraceSnapshot): void {
     const authoritySessionId = traceResultSessionId(result);
     updateTraceMessages(traceId, authoritySessionId, (message) => {
-      const runnerTrace = mergeTerminalResultTrace(message.runnerTrace, result as AgentChatResultResponse);
+      const resultStatus = normalizedStatusText((result as AgentChatResultResponse).status) ?? null;
+      const terminal = (result as AgentChatResultResponse).terminal === true || isTerminalMessageStatus(resultStatus);
+      const resultError = normalizeAgentError((result as AgentChatResultResponse).error ?? null);
+      const resultProjection = projectionFromResult(result as AgentChatResultResponse);
+      const mergedRunnerTrace = mergeTerminalResultTrace(message.runnerTrace, result as AgentChatResultResponse);
+      const runnerTrace = terminal && !resultError && !resultProjection ? clearRunnerTraceTransientDiagnostics(mergedRunnerTrace) : mergedRunnerTrace;
       rememberTraceAuthority(runnerTrace);
-      const error = normalizeAgentError((result as AgentChatResultResponse).error ?? runnerTrace?.error ?? message.error);
+      const error = resultError ?? (terminal ? null : normalizeAgentError(runnerTrace?.error ?? message.error));
       const agentRun = agentRunFromResult(result as AgentChatResultResponse, runnerTrace) ?? agentRunFromMessage(message);
-      const projection = projectionFromResult(result as AgentChatResultResponse) ?? runnerTrace.projection ?? message.projection ?? null;
-      return { ...message, ...messageTimingPatch(result), runnerTrace, error: error ?? message.error ?? null, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
+      const projection = resultProjection ?? (terminal ? null : runnerTrace.projection ?? message.projection ?? null);
+      return { ...message, ...messageTimingPatch(result), runnerTrace, error, projection, projectionStatus: projection?.projectionStatus ?? null, projectionHealth: projection?.projectionHealth ?? null, blocker: projection?.blocker ?? null, agentRun: agentRun ?? undefined, updatedAt: new Date().toISOString() };
     });
   }
 
+  function clearRunnerTraceTransientDiagnostics(trace: NonNullable<ChatMessage["runnerTrace"]>): NonNullable<ChatMessage["runnerTrace"]> {
+    return { ...trace, error: undefined, projection: null, projectionStatus: null, projectionHealth: null, staleMs: null, blocker: null };
+  }
+
   async function submitMessage(text: string): Promise<boolean> {
     const value = text.trim();
     if (!value) return false;