fix(workbench): dedupe final assistant trace rows (#2009)

tools/src/hwlab-cli/trace-renderer.ts

@@ -20,6 +20,7 @@ export function traceDisplayRows(trace: Record<string, unknown> = {}, events: Tr
   const orderedEvents = traceEventsForDisplay(events);
   const effectiveTrace = traceWithInferredStart(trace, orderedEvents);
   const finalResponseText = traceFinalResponseText(effectiveTrace);
+  const finalResponseFingerprint = traceMessageFingerprint(finalResponseText);
   const hasCompletionEvent = orderedEvents.some(isCompletionTraceEvent);
   const rows: TraceEventRow[] = [];
   const renderedSourceEvents = new Set<string>();
@@ -58,6 +59,7 @@ export function traceDisplayRows(trace: Record<string, unknown> = {}, events: Tr
       continue;
     }
     if (isAssistantTraceEvent(event)) {
+      if (finalResponseFingerprint && traceAssistantEventFingerprint(effectiveTrace, event) === finalResponseFingerprint) continue;
       rows.push(traceAssistantMessageRow(effectiveTrace, event, { terminal: false }, options));
       continue;
     }
@@ -214,7 +216,7 @@ export function traceNoiseEventCount(events: TraceEvent[] = []): number {
 }
 
 function traceAssistantMessageRow(trace: Record<string, unknown>, event: TraceEvent, { terminal }: { terminal: boolean }, options: TraceDisplayRowsOptions): TraceEventRow {
-  const text = cleanTraceDetailText(event.message ?? event.outputSummary ?? assistantStreamText(trace, event) ?? "");
+  const text = traceAssistantEventText(trace, event);
   const index = Number.isInteger(event.messageIndex) ? Number(event.messageIndex) : null;
   const count = Number.isInteger(event.messageCount) ? Number(event.messageCount) : null;
   const eventKey = traceEventIdentityToken(event);
@@ -229,6 +231,19 @@ function traceAssistantMessageRow(trace: Record<string, unknown>, event: TraceEv
   };
 }
 
+function traceAssistantEventText(trace: Record<string, unknown>, event: TraceEvent): string {
+  return cleanTraceDetailText(event.message ?? event.outputSummary ?? assistantStreamText(trace, event) ?? "");
+}
+
+function traceAssistantEventFingerprint(trace: Record<string, unknown>, event: TraceEvent): string | null {
+  return traceMessageFingerprint(traceAssistantEventText(trace, event));
+}
+
+function traceMessageFingerprint(value: unknown): string | null {
+  const text = cleanTraceDetailText(value ?? "").replace(/\s+/gu, " ").trim();
+  return text || null;
+}
+
 function traceFinalResponseRow(event: TraceEvent, finalText: string, options: TraceDisplayRowsOptions): TraceEventRow {
   const eventKey = traceEventIdentityToken(event);
   return {