fix: CPU显示修复 + 报表面板添加浏览器池状态

1. CPU 显示修复:
   - routes/admin_api/core.py: 新增 _get_server_cpu_percent()
   - 首次调用使用 interval=0.1 避免返回 0.0
   - 后续调用使用缓存，TTL 1秒

2. 报表面板浏览器池状态:
   - admin-frontend/src/api/browser_pool.js: 新增 API 调用
   - ReportPage.vue: 添加浏览器池状态卡片
   - 显示总/活跃/空闲 Worker 数和队列等待数
   - Worker 表格带状态颜色标签（活跃/空闲/异常）

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

admin-frontend/src/api/browser_pool.js

@@ -0,0 +1,7 @@
+import { api } from './client'
+
+export async function fetchBrowserPoolStats() {
+  const { data } = await api.get('/browser_pool/stats')
+  return data
+}
+

admin-frontend/src/pages/ReportPage.vue

@@ -18,6 +18,7 @@ import {
 import { fetchFeedbackStats } from '../api/feedbacks'
 import { fetchEmailStats } from '../api/email'
 import { fetchDockerStats, fetchRunningTasks, fetchServerInfo, fetchTaskStats } from '../api/tasks'
+import { fetchBrowserPoolStats } from '../api/browser_pool'
 import { fetchSystemConfig } from '../api/system'
 
 const refreshStats = inject('refreshStats', null)
@@ -32,6 +33,7 @@ const emailStats = ref(null)
 const feedbackStats = ref(null)
 const serverInfo = ref(null)
 const dockerStats = ref(null)
+const browserPoolStats = ref(null)
 const systemConfig = ref(null)
 const queueTab = ref('running')
 
@@ -97,6 +99,40 @@ const queuingTaskList = computed(() => runningTasks.value?.queuing || [])
 const runningCount = computed(() => normalizeCount(runningTasks.value?.running_count))
 const queuingCount = computed(() => normalizeCount(runningTasks.value?.queuing_count))
 
+const browserPoolWorkers = computed(() => {
+  const workers = browserPoolStats.value?.workers
+  if (!Array.isArray(workers)) return []
+  return [...workers].sort((a, b) => normalizeCount(a?.worker_id) - normalizeCount(b?.worker_id))
+})
+
+const browserPoolTotalWorkers = computed(() => normalizeCount(browserPoolStats.value?.total_workers))
+const browserPoolActiveWorkers = computed(() => browserPoolWorkers.value.filter((w) => Boolean(w?.has_browser)).length)
+const browserPoolIdleWorkers = computed(() => normalizeCount(browserPoolStats.value?.idle_workers))
+const browserPoolQueueSize = computed(() => normalizeCount(browserPoolStats.value?.queue_size))
+const browserPoolBusyWorkers = computed(() => normalizeCount(browserPoolStats.value?.active_workers))
+
+function workerPoolStatusType(worker) {
+  if (!worker?.thread_alive) return 'danger'
+  if (worker?.has_browser) return 'success'
+  return 'info'
+}
+
+function workerPoolStatusLabel(worker) {
+  if (!worker?.thread_alive) return '异常'
+  if (worker?.has_browser) return '活跃'
+  return '空闲'
+}
+
+function workerRunTagType(worker) {
+  if (!worker?.thread_alive) return 'danger'
+  return worker?.idle ? 'info' : 'warning'
+}
+
+function workerRunLabel(worker) {
+  if (!worker?.thread_alive) return '停止'
+  return worker?.idle ? '空闲' : '忙碌'
+}
+
 const taskTodaySuccessRate = computed(() => {
   const success = normalizeCount(taskToday.value.success_tasks)
   const failed = normalizeCount(taskToday.value.failed_tasks)
@@ -156,6 +192,7 @@ async function refreshAll() {
       feedbackResult,
       serverResult,
       dockerResult,
+      browserPoolResult,
       configResult,
     ] = await Promise.allSettled([
       fetchTaskStats(),
@@ -164,6 +201,7 @@ async function refreshAll() {
       fetchFeedbackStats(),
       fetchServerInfo(),
       fetchDockerStats(),
+      fetchBrowserPoolStats(),
       fetchSystemConfig(),
     ])
 
@@ -173,6 +211,7 @@ async function refreshAll() {
     feedbackStats.value = feedbackResult.status === 'fulfilled' ? feedbackResult.value : null
     serverInfo.value = serverResult.status === 'fulfilled' ? serverResult.value : null
     dockerStats.value = dockerResult.status === 'fulfilled' ? dockerResult.value : null
+    browserPoolStats.value = browserPoolResult.status === 'fulfilled' ? browserPoolResult.value : null
     systemConfig.value = configResult.status === 'fulfilled' ? configResult.value : null
 
     await refreshStats?.()
@@ -548,6 +587,67 @@ onUnmounted(() => {
             <el-descriptions-item label="内存">{{ dockerStats?.memory_usage || '-' }}</el-descriptions-item>
             <el-descriptions-item label="内存占比">{{ dockerStats?.memory_percent || '-' }}</el-descriptions-item>
           </el-descriptions>
+
+          <div class="divider"></div>
+
+          <div class="panel-head">
+            <div class="head-left">
+              <div class="head-text">
+                <div class="panel-title">浏览器池</div>
+                <div class="panel-sub app-muted">
+                  活跃（有浏览器）{{ browserPoolActiveWorkers }} · 忙碌 {{ browserPoolBusyWorkers }} · 队列 {{ browserPoolQueueSize }}
+                </div>
+              </div>
+            </div>
+            <el-tag v-if="browserPoolStats?.server_time_cst" effect="light" type="info">{{ browserPoolStats.server_time_cst }}</el-tag>
+          </div>
+
+          <div class="tile-grid tile-grid--4">
+            <div class="tile">
+              <div class="tile-v">{{ browserPoolTotalWorkers }}</div>
+              <div class="tile-k app-muted">总 Worker</div>
+            </div>
+            <div class="tile">
+              <div class="tile-v ok">{{ browserPoolActiveWorkers }}</div>
+              <div class="tile-k app-muted">活跃（有浏览器）</div>
+            </div>
+            <div class="tile">
+              <div class="tile-v">{{ browserPoolIdleWorkers }}</div>
+              <div class="tile-k app-muted">空闲（无任务）</div>
+            </div>
+            <div class="tile">
+              <div class="tile-v warn">{{ browserPoolQueueSize }}</div>
+              <div class="tile-k app-muted">队列等待</div>
+            </div>
+          </div>
+
+          <div class="divider"></div>
+
+          <div class="table-wrap">
+            <el-table :data="browserPoolWorkers" size="small" border>
+              <el-table-column prop="worker_id" label="Worker" width="90" />
+              <el-table-column label="状态" width="90">
+                <template #default="{ row }">
+                  <el-tag :type="workerPoolStatusType(row)" effect="light">{{ workerPoolStatusLabel(row) }}</el-tag>
+                </template>
+              </el-table-column>
+              <el-table-column label="执行" width="90">
+                <template #default="{ row }">
+                  <el-tag :type="workerRunTagType(row)" effect="light">{{ workerRunLabel(row) }}</el-tag>
+                </template>
+              </el-table-column>
+              <el-table-column label="任务" width="120">
+                <template #default="{ row }">
+                  <span>{{ normalizeCount(row?.total_tasks) }}</span>
+                  <span class="app-muted"> / </span>
+                  <span :class="normalizeCount(row?.failed_tasks) ? 'err' : 'app-muted'">{{ normalizeCount(row?.failed_tasks) }}</span>
+                </template>
+              </el-table-column>
+              <el-table-column prop="browser_use_count" label="复用" width="90" />
+              <el-table-column prop="last_active_at" label="最近活跃" min-width="160" />
+              <el-table-column prop="browser_created_at" label="浏览器创建" min-width="160" />
+            </el-table>
+          </div>
         </el-card>
       </el-col>
 
@@ -901,6 +1001,10 @@ onUnmounted(() => {
   grid-template-columns: repeat(3, minmax(0, 1fr));
 }
 
+.tile-grid--4 {
+  grid-template-columns: repeat(4, minmax(0, 1fr));
+}
+
 .tile {
   border: 1px solid rgba(17, 24, 39, 0.08);
   border-radius: 16px;
@@ -1072,6 +1176,10 @@ onUnmounted(() => {
     grid-template-columns: repeat(2, minmax(0, 1fr));
   }
 
+  .tile-grid--4 {
+    grid-template-columns: repeat(2, minmax(0, 1fr));
+  }
+
   .resource-grid {
     grid-template-columns: 1fr;
   }