diff --git a/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue b/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
index f120becb..17882873 100644
--- a/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
+++ b/web/hwlab-cloud-web/src/components/agent/TraceTimeline.vue
@@ -1,14 +1,15 @@
 <script setup lang="ts">
 import { computed, nextTick, ref, watch } from "vue";
 import type { RunnerTrace, TraceEvent } from "@/types";
+import { isTerminalStatus } from "@/composables/useTraceSubscription";
 import { firstNonEmptyString } from "@/utils";
 import { traceEventBody, traceEventLabel, traceEventMeta, visibleTraceEvents } from "@/components/workbench/message-rendering";
 
-const props = defineProps<{ trace?: RunnerTrace | null }>();
+const props = defineProps<{ trace?: RunnerTrace | null; defaultExpanded?: boolean; storageKey?: string }>();
 
 const listRef = ref<HTMLOListElement | null>(null);
 const following = ref(true);
-const expanded = ref(true);
+const expanded = ref(false);
 const compact = ref(true);
 
 const events = computed(() => Array.isArray(props.trace?.events) ? props.trace.events : []);
@@ -24,6 +25,15 @@ watch(() => [eventCount.value, props.trace?.status, following.value, expanded.va
   jumpToBottom();
 });
 
+watch(() => [props.trace?.traceId, props.trace?.status, props.defaultExpanded] as const, () => {
+  expanded.value = props.defaultExpanded ?? !isTerminalStatus(props.trace?.status);
+}, { immediate: true });
+
+watch(expanded, (value) => {
+  if (!props.storageKey) return;
+  try { window.localStorage.setItem(props.storageKey, value ? "1" : "0"); } catch { /* ignore */ }
+});
+
 function jumpToBottom(): void {
   const list = listRef.value;
   if (!list) return;
diff --git a/web/hwlab-cloud-web/src/components/hwpod/HwpodNodeOpsPanel.vue b/web/hwlab-cloud-web/src/components/hwpod/HwpodNodeOpsPanel.vue
index c16faced..285af494 100644
--- a/web/hwlab-cloud-web/src/components/hwpod/HwpodNodeOpsPanel.vue
+++ b/web/hwlab-cloud-web/src/components/hwpod/HwpodNodeOpsPanel.vue
@@ -8,6 +8,7 @@ import { useWorkbenchStore } from "@/stores/workbench";
 const hwpod = useHwpodStore();
 const workbench = useWorkbenchStore();
 const selectedDetail = ref<HwpodDetail | null>(null);
+const diagnosticsOpen = ref(false);
 const follow = ref(true);
 const scrollRef = ref<HTMLDivElement | null>(null);
 const summary = computed(() => summarizeHwpodNodeOps({ live: workbench.live, specs: hwpod.specs, nodeOps: hwpod.nodeOps, error: hwpod.error }));
@@ -39,42 +40,11 @@ function onStreamScroll(): void {
         <p class="page-eyebrow">HWPOD</p>
         <h2>Node Ops</h2>
       </div>
-      <StatusBadge :status="summary.tone" :label="`node-ops ${summary.status}`" />
-    </div>
-    <div class="evidence-grid" aria-label="HWPOD evidence level">
-      <span>DEV-LIVE</span>
-      <span>SOURCE</span>
-      <span>LOCAL</span>
-      <span>DRY-RUN</span>
-      <span>BLOCKED</span>
-    </div>
-    <section class="hwpod-node-status" aria-label="HWPOD node-ops status">
-      <div class="hwpod-node-summary" id="hwpod-node-summary">
-        <button v-for="tile in summary.tiles" :key="tile.key" class="summary-tile" type="button" :data-hwpod-detail="tile.key" :data-hwpod-title="tile.detail.title" @click="selectedDetail = tile.detail">
-          <span>{{ tile.label }}</span>
-          <strong>{{ tile.value }}</strong>
-        </button>
+      <div class="hwpod-panel-actions">
+        <StatusBadge :status="summary.tone" :label="`node-ops ${summary.status}`" />
+        <button class="hwpod-diagnostics-button" type="button" aria-label="HWPOD 诊断" aria-haspopup="dialog" @click="diagnosticsOpen = true">!</button>
       </div>
-      <dl class="hwpod-node-meta">
-        <div><dt>hwpod</dt><dd>{{ summary.hwpodName }}</dd></div>
-        <div><dt>node</dt><dd>{{ summary.nodeId }}</dd></div>
-        <div><dt>workspace</dt><dd>{{ summary.workspacePath }}</dd></div>
-        <div><dt>case</dt><dd>{{ summary.caseId }}</dd></div>
-        <div><dt>route</dt><dd>{{ summary.route }}</dd></div>
-        <div><dt>updated</dt><dd>{{ formatTimestamp(summary.updatedAt) }}</dd></div>
-        <div><dt>ws</dt><dd>{{ summary.connectedCount }} connected / {{ summary.pendingCount }} pending</dd></div>
-        <div><dt>supported ops</dt><dd>{{ summary.supportedOpsCount }}</dd></div>
-      </dl>
-    </section>
-    <section v-if="summary.errors.length" class="hwpod-errors" aria-label="HWPOD blockers">
-      <strong>阻塞聚合</strong>
-      <ul>
-        <li v-for="error in summary.errors" :key="error.key">
-          <code>{{ error.code }}</code>
-          <span>{{ error.message }}</span>
-        </li>
-      </ul>
-    </section>
+    </div>
     <section class="hwpod-event-panel" aria-label="node-ops 流">
       <header>
         <span>node-ops</span>
@@ -87,6 +57,51 @@ function onStreamScroll(): void {
         <pre id="hwpod-event-text">{{ summary.streamLines.join('\n') || '等待 HWPOD node-ops。' }}</pre>
       </div>
     </section>
+    <div v-if="diagnosticsOpen" class="workbench-dialog-backdrop" role="presentation" @click.self="diagnosticsOpen = false">
+      <section id="hwpod-diagnostics-dialog" class="workbench-dialog wide" role="dialog" aria-modal="true" aria-labelledby="hwpod-diagnostics-title">
+        <header>
+          <div class="dialog-title-stack">
+            <h2 id="hwpod-diagnostics-title">HWPOD 诊断</h2>
+            <p>{{ summary.hwpodName }} / {{ summary.nodeId }} / {{ formatTimestamp(summary.updatedAt) }}</p>
+          </div>
+          <button type="button" class="dialog-close" aria-label="关闭" @click="diagnosticsOpen = false">x</button>
+        </header>
+        <div class="evidence-grid" aria-label="HWPOD evidence level">
+          <span>DEV-LIVE</span>
+          <span>SOURCE</span>
+          <span>LOCAL</span>
+          <span>DRY-RUN</span>
+          <span>BLOCKED</span>
+        </div>
+        <section class="hwpod-node-status" aria-label="HWPOD node-ops status">
+          <div class="hwpod-node-summary" id="hwpod-node-summary">
+            <button v-for="tile in summary.tiles" :key="tile.key" class="summary-tile" type="button" :data-hwpod-detail="tile.key" :data-hwpod-title="tile.detail.title" @click="selectedDetail = tile.detail">
+              <span>{{ tile.label }}</span>
+              <strong>{{ tile.value }}</strong>
+            </button>
+          </div>
+          <dl class="hwpod-node-meta">
+            <div><dt>hwpod</dt><dd>{{ summary.hwpodName }}</dd></div>
+            <div><dt>node</dt><dd>{{ summary.nodeId }}</dd></div>
+            <div><dt>workspace</dt><dd>{{ summary.workspacePath }}</dd></div>
+            <div><dt>case</dt><dd>{{ summary.caseId }}</dd></div>
+            <div><dt>route</dt><dd>{{ summary.route }}</dd></div>
+            <div><dt>updated</dt><dd>{{ formatTimestamp(summary.updatedAt) }}</dd></div>
+            <div><dt>ws</dt><dd>{{ summary.connectedCount }} connected / {{ summary.pendingCount }} pending</dd></div>
+            <div><dt>supported ops</dt><dd>{{ summary.supportedOpsCount }}</dd></div>
+          </dl>
+        </section>
+        <section v-if="summary.errors.length" class="hwpod-errors" aria-label="HWPOD blockers">
+          <strong>阻塞聚合</strong>
+          <ul>
+            <li v-for="error in summary.errors" :key="error.key">
+              <code>{{ error.code }}</code>
+              <span>{{ error.message }}</span>
+            </li>
+          </ul>
+        </section>
+      </section>
+    </div>
     <div v-if="selectedDetail" class="workbench-dialog-backdrop" role="presentation" @click.self="selectedDetail = null">
       <section id="hwpod-detail-dialog" class="workbench-dialog" role="dialog" aria-modal="true" aria-labelledby="hwpod-detail-title">
         <header>
diff --git a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
index 4dbe9224..a1422504 100644
--- a/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
+++ b/web/hwlab-cloud-web/src/components/workbench/ConversationPanel.vue
@@ -6,6 +6,7 @@ import TraceTimeline from "@/components/agent/TraceTimeline.vue";
 import CodeAgentStatusSummary from "@/components/workbench/CodeAgentStatusSummary.vue";
 import MessageActions from "@/components/workbench/MessageActions.vue";
 import MessageMarkdown from "@/components/workbench/MessageMarkdown.vue";
+import { isTerminalStatus } from "@/composables/useTraceSubscription";
 import { useClipboard } from "@/composables/useClipboard";
 import { useWorkbenchStore } from "@/stores/workbench";
 import { traceIdentityText } from "./message-rendering";
@@ -18,6 +19,14 @@ const detailMessage = computed(() => workbench.messages.find((message) => messag
 function openDetails(message: ChatMessage): void {
   detailMessageId.value = message.id;
 }
+
+function traceDefaultExpanded(message: ChatMessage): boolean {
+  return !isTerminalStatus(message.runnerTrace?.status ?? message.status);
+}
+
+function traceStorageKey(message: ChatMessage): string {
+  return `hwlab.workbench.trace-open.${message.traceId ?? message.runnerTrace?.traceId ?? message.id}`;
+}
 </script>
 
 <template>
@@ -30,12 +39,10 @@ function openDetails(message: ChatMessage): void {
           <button v-if="message.role === 'agent'" class="message-detail-button" type="button" aria-label="消息详情" title="消息详情" @click="openDetails(message)">i</button>
         </div>
       </header>
+      <TraceTimeline v-if="message.role === 'agent' && message.runnerTrace" :trace="message.runnerTrace" :default-expanded="traceDefaultExpanded(message)" :storage-key="traceStorageKey(message)" />
       <MessageMarkdown class="message-text" :source="message.text" />
     </article>
-    <article v-if="workbench.messages.length === 0" class="message-card empty-message">
-      <header><strong>等待会话</strong><StatusBadge status="source" label="SOURCE" /></header>
-      <MessageMarkdown class="message-text" source="请先显式新建或选择 session。Code Agent 不会自动滚动新 session 掩盖失败。" />
-    </article>
+    <div v-if="workbench.messages.length === 0" class="conversation-empty-hint">发起对话，或从左侧选择 session。</div>
     <div v-if="detailMessage" class="workbench-dialog-backdrop" role="presentation" @click.self="detailMessageId = null">
       <section id="message-detail-dialog" class="workbench-dialog wide" role="dialog" aria-modal="true" aria-labelledby="message-detail-title">
         <header>
@@ -45,7 +52,6 @@ function openDetails(message: ChatMessage): void {
           </div>
           <button type="button" class="dialog-close" aria-label="关闭" @click="detailMessageId = null">x</button>
         </header>
-        <TraceTimeline :trace="detailMessage.runnerTrace" />
         <CodeAgentStatusSummary :message="detailMessage" />
         <MessageActions
           :message="detailMessage"
diff --git a/web/hwlab-cloud-web/src/styles/workbench.css b/web/hwlab-cloud-web/src/styles/workbench.css
index 429a7b3b..ad79dd44 100644
--- a/web/hwlab-cloud-web/src/styles/workbench.css
+++ b/web/hwlab-cloud-web/src/styles/workbench.css
@@ -48,10 +48,9 @@
 }
 
 .platform-content {
-  display: grid;
   min-height: 0;
   min-width: 0;
-  overflow: hidden;
+  overflow: auto;
   padding: 22px;
 }
 
@@ -108,7 +107,8 @@
 }
 
 .route-stack {
-  overflow: auto;
+  align-content: start;
+  overflow: visible;
 }
 
 .workbench-route {
@@ -558,7 +558,10 @@
 }
 
 .hwpod-panel {
-  grid-template-rows: auto auto minmax(0, auto) auto minmax(0, 1fr);
+  align-content: stretch;
+  grid-template-rows: auto minmax(220px, 1fr);
+  overflow: auto;
+  overscroll-behavior: contain;
 }
 
 .panel-header {
@@ -623,6 +626,13 @@
   padding: 14px;
 }
 
+.conversation-empty-hint {
+  justify-self: center;
+  margin-top: 24px;
+  color: #64748b;
+  font-size: 13px;
+}
+
 .message-card {
   display: grid;
   align-self: start;
@@ -630,6 +640,10 @@
   padding: 12px;
 }
 
+.message-card[data-role="agent"] {
+  width: 100%;
+}
+
 .message-card[data-role="user"] {
   justify-self: end;
   width: max-content;
@@ -1045,6 +1059,28 @@
   font-weight: 750;
 }
 
+.hwpod-panel-actions {
+  display: inline-flex;
+  min-width: 0;
+  flex: 0 0 auto;
+  align-items: center;
+  gap: 8px;
+}
+
+.hwpod-diagnostics-button {
+  display: inline-flex;
+  width: 28px;
+  height: 28px;
+  align-items: center;
+  justify-content: center;
+  border: 1px solid #cbd5e1;
+  border-radius: 999px;
+  background: white;
+  color: #0c4a6e;
+  font-size: 13px;
+  font-weight: 900;
+}
+
 .hwpod-node-status,
 .hwpod-event-panel {
   display: grid;
@@ -1058,6 +1094,7 @@
 
 .hwpod-event-panel {
   grid-template-rows: auto minmax(0, 1fr);
+  min-height: 0;
 }
 
 .hwpod-node-summary {
@@ -1164,7 +1201,6 @@
 
 .hwpod-event-scroll {
   min-height: 0;
-  max-height: none;
   overflow: auto;
   border: 1px solid #d8e1eb;
   border-radius: 8px;
@@ -1197,6 +1233,7 @@
 
 .empty-state {
   display: grid;
+  align-self: start;
   justify-items: start;
   gap: 8px;
 }
@@ -1895,7 +1932,7 @@
   }
 
   .workbench-route {
-    height: auto;
+    min-height: calc(100dvh - 102px);
     overflow: auto;
   }
 
@@ -1903,7 +1940,7 @@
   .session-rail,
   .workbench-center,
   .hwpod-panel {
-    height: auto;
+    min-height: 0;
   }
 
   .hwpod-event-scroll {