feat: real-time activity indicator in log panel

- New WsMessage::ActivityUpdate for live status broadcasting
- Shows current activity at bottom of log: LLM calls, tool execution, user approval
- Activity bar with spinner, auto-clears on workflow completion
- Status badge with pulse animation in log header

web/src/components/ExecutionSection.vue

@@ -12,6 +12,7 @@ const props = defineProps<{
   createdAt: string
   workflowStatus: string
   workflowId: string
+  currentActivity: string
 }>()
 
 const emit = defineEmits<{
@@ -278,6 +279,10 @@ watch(logItems, () => {
           </div>
         </div>
       </template>
+      <div v-if="currentActivity" class="activity-bar">
+        <span class="activity-spinner" />
+        <span class="activity-text">{{ currentActivity }}</span>
+      </div>
       <div v-if="!entries.length && !requirement" class="empty-state">
         提交需求后，日志将显示在这里
       </div>
@@ -529,6 +534,36 @@ watch(logItems, () => {
   margin: 0;
 }
 
+.activity-bar {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 10px 12px;
+  border-radius: 6px;
+  background: rgba(79, 195, 247, 0.08);
+  border: 1px dashed var(--accent);
+  font-size: 13px;
+  color: var(--accent);
+}
+
+.activity-spinner {
+  width: 14px;
+  height: 14px;
+  border: 2px solid var(--accent);
+  border-top-color: transparent;
+  border-radius: 50%;
+  animation: spin 0.8s linear infinite;
+  flex-shrink: 0;
+}
+
+@keyframes spin {
+  to { transform: rotate(360deg); }
+}
+
+.activity-text {
+  font-weight: 500;
+}
+
 .empty-state {
   color: var(--text-secondary);
   font-size: 13px;

web/src/components/WorkflowView.vue

@@ -24,6 +24,7 @@ const planSteps = ref<PlanStepInfo[]>([])
 const comments = ref<Comment[]>([])
 const llmCalls = ref<LlmCallLogEntry[]>([])
 const quotes = ref<string[]>([])
+const currentActivity = ref('')
 const error = ref('')
 const rightTab = ref<'log' | 'timers'>('log')
 const commentRef = ref<InstanceType<typeof CommentSection> | null>(null)
@@ -92,6 +93,14 @@ function handleWsMessage(msg: WsMessage) {
     case 'WorkflowStatusUpdate':
       if (workflow.value && msg.workflow_id === workflow.value.id) {
         workflow.value = { ...workflow.value, status: msg.status as any }
+        if (msg.status === 'done' || msg.status === 'failed') {
+          currentActivity.value = ''
+        }
+      }
+      break
+    case 'ActivityUpdate':
+      if (workflow.value && msg.workflow_id === workflow.value.id) {
+        currentActivity.value = msg.activity
       }
       break
     case 'RequirementUpdate':
@@ -186,6 +195,7 @@ async function onSubmitComment(text: string) {
           :createdAt="workflow?.created_at || ''"
           :workflowStatus="workflow?.status || 'pending'"
           :workflowId="workflow?.id || ''"
+          :currentActivity="currentActivity"
           @quote="addQuote"
         />
         <TimerSection

web/src/ws.ts

@@ -40,12 +40,18 @@ export interface WsLlmCallLog {
   entry: import('./types').LlmCallLogEntry
 }
 
+export interface WsActivityUpdate {
+  type: 'ActivityUpdate'
+  workflow_id: string
+  activity: string
+}
+
 export interface WsError {
   type: 'Error'
   message: string
 }
 
-export type WsMessage = WsPlanUpdate | WsStepStatusUpdate | WsWorkflowStatusUpdate | WsRequirementUpdate | WsReportReady | WsProjectUpdate | WsLlmCallLog | WsError
+export type WsMessage = WsPlanUpdate | WsStepStatusUpdate | WsWorkflowStatusUpdate | WsRequirementUpdate | WsReportReady | WsProjectUpdate | WsLlmCallLog | WsActivityUpdate | WsError
 
 export type WsHandler = (msg: WsMessage) => void