fix: clarify Workbench session title fallback

web/hwlab-cloud-web/src/components/workbench/SessionRail.vue

@@ -106,8 +106,8 @@ function formatSessionUpdatedTime(value: string | null | undefined): string {
     <div v-if="!collapsed" class="session-list" id="session-tabs" :data-loading="showSessionListLoading">
       <LoadingState v-if="showSessionListLoading" class="session-list-loading" label="加载中" />
       <template v-else>
-        <button v-for="tab in workbench.sessionTabs" :key="tab.sessionId || tab.key" class="session-tab" :data-active="tab.active" :data-running="tab.running" :data-status="tab.status || undefined" :data-projection-health="tab.projectionHealth || undefined" :data-session-id="tab.sessionId || undefined" type="button" :title="tab.projectionDiagnosticText || tab.label || tab.sessionId || tab.key" @click="workbench.selectSession(tab)">
-          <span class="session-tab-title">{{ tab.label || tab.sessionId }}</span>
+        <button v-for="tab in workbench.sessionTabs" :key="tab.sessionId || tab.key" class="session-tab" :data-active="tab.active" :data-running="tab.running" :data-status="tab.status || undefined" :data-projection-health="tab.projectionHealth || undefined" :data-session-id="tab.sessionId || undefined" type="button" :title="tab.tooltip" @click="workbench.selectSession(tab)">
+          <span class="session-tab-title">{{ tab.label }}</span>
           <span v-if="tab.projectionDiagnosticText" class="session-tab-diagnostic">状态更新异常</span>
           <time class="session-tab-time" :datetime="tab.updatedAt || tab.startedAt || undefined">{{ formatSessionUpdatedTime(tab.updatedAt || tab.startedAt) }}</time>
         </button>

web/hwlab-cloud-web/src/stores/workbench-session.test.ts

@@ -165,3 +165,19 @@ test("session rail update time uses the last user send time instead of replay re
 
   assert.equal(tab.updatedAt, "2026-07-20T00:00:00.000Z");
 });
+
+test("session rail uses a neutral label when Kafka has no user title event", () => {
+  const sessionId = "ses_session_rail_without_kafka_title";
+  const tab = sessionToSessionTab({ sessionId, messages: [] }, null);
+
+  assert.equal(tab.label, "新建会话");
+  assert.equal(tab.tooltip, `新建会话 · ${sessionId}`);
+});
+
+test("session rail keeps the Kafka user preview as its visible title", () => {
+  const sessionId = "ses_session_rail_with_kafka_title";
+  const tab = sessionToSessionTab({ sessionId, firstUserMessagePreview: "hi", messages: [] }, null);
+
+  assert.equal(tab.label, "hi");
+  assert.equal(tab.tooltip, `hi · ${sessionId}`);
+});

web/hwlab-cloud-web/src/stores/workbench-session.ts

@@ -18,6 +18,7 @@ export interface ComposerState {
 export interface SessionTab extends WorkbenchSessionRecord {
   key: string;
   label: string;
+  tooltip: string;
   subtitle: string;
   active: boolean;
   running: boolean;
@@ -162,10 +163,12 @@ export function sessionToSessionTab(session: WorkbenchSessionRecord, activeSessi
     session.title,
     session.name
   );
+  const label = preview ?? "新建会话";
   return {
     ...session,
     key: sessionId,
-    label: preview ?? `Session ${shortToken(sessionId, 8)}`,
+    label,
+    tooltip: `${projectionText ?? label} · ${sessionId}`,
     subtitle: `${projectionText ? "状态更新异常" : running ? "处理中" : trace ? `trace ${shortToken(trace, 8)}` : status === "unknown" ? "状态同步中" : "未开始"} · ${session.messageCount ?? session.messages?.length ?? 0} 条`,
     lastTraceId: trace,
     status,