diff --git a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
index 5fd38bf5..9c883ca5 100644
--- a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
+++ b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
@@ -26,8 +26,6 @@ const clipboard = useClipboard();
 const panelRef = ref<HTMLElement | null>(null);
 const { following, keepBottomAfterUpdate, onScroll: onPanelScroll, scrollToBottom } = useBottomFollowScroll(panelRef, { threshold: 56 });
 const detailMessageId = ref<string | null>(null);
-const displayedDurationFloorMs = new Map<string, number>();
-const sealedDurationMs = new Map<string, number>();
 const visibleMessages = computed(() => workbench.sessionDetailLoading ? [] : workbench.activeMessages);
 const hasRunningAgentMessages = computed(() => visibleMessages.value.some(isRunningMessage));
 const { nowMs } = useWorkbenchNowTicker(hasRunningAgentMessages);
@@ -58,16 +56,6 @@ watch(() => workbench.sessionDetailLoading, async () => {
   acknowledgeVisibleMessages();
 });
 
-watch(visibleMessages, (messages) => {
-  const visibleKeys = new Set(messages.map(messageDurationFloorKey));
-  for (const key of Array.from(displayedDurationFloorMs.keys())) {
-    if (!visibleKeys.has(key)) displayedDurationFloorMs.delete(key);
-  }
-  for (const key of Array.from(sealedDurationMs.keys())) {
-    if (!visibleKeys.has(key)) sealedDurationMs.delete(key);
-  }
-}, { immediate: true });
-
 function openDetails(message: ChatMessage): void {
   detailMessageId.value = message.id;
 }
@@ -259,63 +247,12 @@ function traceForDisplay(message: ChatMessage): ChatMessage["runnerTrace"] {
 function messageDurationMeta(message: ChatMessage): { text: string; label: string } | null {
   if (message.role !== "agent") return null;
   const timing = messageTimingForDisplay(message);
-  const rawDurationMs = isRunningMessage(message) ? durationSince(timing?.startedAt) : terminalMessageDurationMs(message, timing);
-  const durationMs = isRunningMessage(message) ? monotonicDisplayDurationMs(message, rawDurationMs) : sealedDisplayDurationMs(message, rawDurationMs);
+  const durationMs = isRunningMessage(message) ? durationSince(timing?.startedAt) : terminalMessageDurationMs(message, timing);
   if (durationMs === null) return null;
   const value = formatDuration(durationMs);
   return { text: `耗时 ${value}`, label: `总耗时：${value}` };
 }
 
-function monotonicDisplayDurationMs(message: ChatMessage, durationMs: number | null): number | null {
-  if (durationMs === null) return null;
-  const key = messageDurationFloorKey(message);
-  const previous = displayedDurationFloorMs.get(key);
-  const next = previous === undefined ? durationMs : Math.max(previous, durationMs);
-  if (next !== previous) displayedDurationFloorMs.set(key, next);
-  return next;
-}
-
-function sealedDisplayDurationMs(message: ChatMessage, durationMs: number | null): number | null {
-  const key = messageDurationFloorKey(message);
-  const runningFloor = displayedDurationFloorMs.get(key);
-  const sealedFloor = sealedDurationMs.get(key);
-  const previous = maxDefinedDurationMs(runningFloor, sealedFloor);
-  displayedDurationFloorMs.delete(key);
-  if (durationMs === null) return previous ?? null;
-  const next = previous === null ? durationMs : Math.max(previous, durationMs);
-  if (next !== previous) sealedDurationMs.set(key, next);
-  return next;
-}
-
-function maxDefinedDurationMs(...values: Array<number | undefined>): number | null {
-  let maximum: number | null = null;
-  for (const value of values) {
-    if (typeof value !== "number" || !Number.isFinite(value)) continue;
-    maximum = maximum === null ? value : Math.max(maximum, value);
-  }
-  return maximum;
-}
-
-function messageDurationFloorKey(message: ChatMessage): string {
-  const primary = firstNonEmptyString(message.traceId, message.runnerTrace?.traceId, message.turnId, message.id) ?? "unknown-agent-message";
-  migrateVisibleTimingAliases(primary, [message.id, message.runnerTrace?.traceId, message.traceId, message.turnId]);
-  return primary;
-}
-
-function migrateVisibleTimingAliases(primary: string, aliases: unknown[]): void {
-  for (const aliasValue of aliases) {
-    if (typeof aliasValue !== "string") continue;
-    const alias = aliasValue.trim();
-    if (!alias || alias === primary) continue;
-    const timingSample = visibleTimingSamples.get(alias);
-    if (timingSample && !visibleTimingSamples.has(primary)) visibleTimingSamples.set(primary, { ...timingSample });
-    const displayedDuration = displayedDurationFloorMs.get(alias);
-    if (displayedDuration !== undefined && displayedDurationFloorMs.get(primary) === undefined) displayedDurationFloorMs.set(primary, displayedDuration);
-    const sealedDuration = sealedDurationMs.get(alias);
-    if (sealedDuration !== undefined && sealedDurationMs.get(primary) === undefined) sealedDurationMs.set(primary, sealedDuration);
-  }
-}
-
 function messageActivityMeta(message: ChatMessage): { text: string; label: string } | null {
   if (!isRunningMessage(message)) return null;
   const timing = messageTimingForDisplay(message);