fix: lazy render Workbench tool output

web/hwlab-cloud-web/src/components/agent/TraceTimeline.test.ts

@@ -269,6 +269,13 @@ describe("TraceTimeline sequence authority", () => {
     expect(completedSummary.get("code").text()).toMatch(/^\d{2}:\d{2}:\d{2}$/u);
     expect(completedSummary.get(".trace-tool-command-preview").text()).toBe("bun test tool-state");
     expect(completedSummary.text()).not.toMatch(/\b(?:ok|fail|run|running)\b|total=|duration=|exit=|工具调用成功/u);
+    expect(completedDetails.text()).not.toContain("1 test passed");
+
+    completedDetails.element.open = true;
+    await completedDetails.trigger("toggle");
+    await nextTick();
+
+    expect(completedDetails.text()).toContain("1 test passed");
     wrapper.unmount();
   });
 
@@ -307,6 +314,51 @@ describe("TraceTimeline sequence authority", () => {
     expect(wrapper.text()).toContain("共 1000 events");
     wrapper.unmount();
   });
+
+  it("does not mount folded tool output bodies for a dense live Trace", async () => {
+    const events = Array.from({ length: 120 }, (_, index) => ({
+      sourceEventId: `evt_tool_dense_${index + 1}`,
+      runId: "run_tool_dense",
+      sourceSeq: index + 1,
+      source: "agentrun.kafka",
+      type: "tool_call",
+      label: "agentrun:tool:completed",
+      status: "completed",
+      toolName: "commandExecution",
+      itemId: `tool_dense_${index + 1}`,
+      command: `rg dense-${index + 1}`,
+      stdoutSummary: `dense output ${index + 1}`,
+      exitCode: 0
+    }));
+    const wrapper = mount(TraceTimeline, {
+      props: {
+        autoExpanded: true,
+        trace: {
+          traceId: "trc_tool_dense",
+          eventSource: "hwlab-kafka-sse",
+          status: "running",
+          eventCount: events.length,
+          events
+        }
+      }
+    });
+    await nextTick();
+
+    const tools = wrapper.findAll(".trace-tool-details");
+    expect(tools).toHaveLength(120);
+    expect(wrapper.findAll(".trace-tool-details .trace-row-body")).toHaveLength(0);
+
+    const lastTool = tools.at(-1);
+    expect(lastTool).toBeDefined();
+    if (!lastTool) throw new Error("last tool row was not rendered");
+    lastTool.element.open = true;
+    await lastTool.trigger("toggle");
+    await nextTick();
+
+    expect(wrapper.findAll(".trace-tool-details .trace-row-body")).toHaveLength(1);
+    expect(lastTool.text()).toContain("dense output 120");
+    wrapper.unmount();
+  });
 });
 
 function liveTrace(status: "running" | "completed") {

web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue

@@ -22,6 +22,7 @@ const TRACE_RENDER_ROW_WINDOW = 120;
 const TRACE_RENDER_EVENT_WINDOW = TRACE_RENDER_ROW_WINDOW * 2;
 const listRef = ref<HTMLOListElement | null>(null);
 const expanded = ref(false);
+const expandedToolRowIds = ref(new Set<string>());
 const { following, keepBottomAfterUpdate, onScroll, scrollToBottom } = useWorkbenchBottomFollowScroll(listRef, { threshold: 24 });
 
 const events = computed(() => Array.isArray(props.trace?.events) ? props.trace.events : []);
@@ -104,6 +105,13 @@ function onDisclosureToggle(event: Event): void {
   writeStoredExpanded(target.open);
 }
 
+function onToolDisclosureToggle(row: TraceEventRow, event: Event): void {
+  const target = event.currentTarget;
+  if (!(target instanceof HTMLDetailsElement)) return;
+  if (target.open) expandedToolRowIds.value.add(row.rowId);
+  else expandedToolRowIds.value.delete(row.rowId);
+}
+
 function setExpandedProgrammatically(value: boolean): void {
   if (expanded.value === value) return;
   programmaticToggleTarget = value;
@@ -175,14 +183,16 @@ function firstNonEmptyString(...values: unknown[]): string | null {
         <p v-if="hiddenRowCount > 0 || inputEventWindowed" class="trace-window-notice">显示最近 {{ renderedRows.length }} 行，共 {{ eventCount }} events</p>
         <ol v-if="renderedRows.length > 0" ref="listRef" @scroll="onScroll">
           <li v-for="(row, index) in renderedRows" :key="rowKey(row, index)" class="trace-render-row" data-testid="trace-render-row" :data-trace-id="trace.traceId || undefined" :data-event-seq="row.seq ?? undefined" :data-event-seq-authority="row.sequenceAuthority" :data-projected-seq="row.sequenceAuthority === 'projected' ? row.seq ?? undefined : undefined" :data-event-kind="row.rowId" :data-event-status="row.tone" :data-tool-state="row.toolState ?? undefined" :data-terminal="row.terminal ? 'true' : 'false'" :data-row-kind="rowIsTool(row) ? 'tool' : 'message'" :data-row-id="row.rowId" :aria-posinset="hiddenRowCount + index + 1">
-            <details v-if="rowIsTool(row)" class="trace-tool-details" :aria-busy="row.toolState === 'running' ? 'true' : undefined">
+            <details v-if="rowIsTool(row)" class="trace-tool-details" :aria-busy="row.toolState === 'running' ? 'true' : undefined" @toggle="onToolDisclosureToggle(row, $event)">
               <summary :aria-label="traceToolAccessibilityLabel(row)" :title="traceToolAccessibilityLabel(row)" aria-live="polite" aria-atomic="true">
                 <code>{{ row.header }}</code>
                 <span v-if="toolCommandPreview(row)" class="trace-tool-command-preview">{{ toolCommandPreview(row) }}</span>
               </summary>
-              <MessageMarkdown v-if="row.body && row.bodyFormat === 'markdown'" class="trace-row-body trace-row-markdown" :source="row.body" />
-              <pre v-else-if="row.body" class="trace-row-body">{{ row.body }}</pre>
-              <span v-else class="trace-row-body muted">已记录</span>
+              <template v-if="expandedToolRowIds.has(row.rowId)">
+                <MessageMarkdown v-if="row.body && row.bodyFormat === 'markdown'" class="trace-row-body trace-row-markdown" :source="row.body" />
+                <pre v-else-if="row.body" class="trace-row-body">{{ row.body }}</pre>
+                <span v-else class="trace-row-body muted">已记录</span>
+              </template>
             </details>
             <template v-else>
               <code>{{ row.header }}</code>