feat(frontend): polish cluster usage bars, task times and sidebar default

- cluster list: rebuild CPU usage bars with progressbar semantics, NaN/out-of-range clamping and three-tier tone colors for cluster and node tables
- task center: show task creation time next to runner with full timestamp on hover and invalid-date fallbacks
- sidebar: collapse portal group by default

frontend/src/components/Layout/AppSidebar.vue

@@ -100,7 +100,7 @@ import { taskLogApi } from '@/api/taskLog'
 const route = useRoute()
 const authStore = useAuthStore()
 const businessLineStore = useBusinessLineStore()
-const portalExpanded = ref(true)
+const portalExpanded = ref(false)
 const isPlatformAdmin = computed(() => authStore.isAdmin)
 const isBusinessLineAdmin = computed(() => businessLineStore.isCurrentAdmin)
 const sidebarBadges = ref({

frontend/src/views/cluster/ClusterList.vue

@@ -39,7 +39,22 @@
               <td :class="['status-text', cluster.statusClass]">● {{ cluster.status }}</td>
               <td class="mono">{{ cluster.nodes }}</td>
               <td>
-                <span class="bar-wrap"><span class="bar-fill" :class="cluster.cpuClass" :style="{ width: cluster.cpu + '%' }"></span></span>{{ cluster.cpu }}%
+                <div class="usage-cell">
+                  <span
+                    class="usage-track"
+                    role="progressbar"
+                    aria-label="CPU 使用率"
+                    aria-valuemin="0"
+                    aria-valuemax="100"
+                    :aria-valuenow="normalizeUsage(cluster.cpu)"
+                  >
+                    <span
+                      :class="['usage-fill', usageTone(cluster.cpu)]"
+                      :style="{ width: `${normalizeUsage(cluster.cpu)}%` }"
+                    ></span>
+                  </span>
+                  <span class="usage-value mono">{{ normalizeUsage(cluster.cpu) }}%</span>
+                </div>
               </td>
               <td class="mono">{{ cluster.version }}</td>
               <td class="mono">{{ cluster.calico }}</td>
@@ -80,7 +95,22 @@
               <td class="mono">{{ node.spec }}</td>
               <td>
                 <template v-if="node.cpu > 0">
-                  <span class="bar-wrap"><span class="bar-fill" :class="node.cpuClass" :style="{ width: node.cpu + '%' }"></span></span>{{ node.cpu }}%
+                  <div class="usage-cell">
+                    <span
+                      class="usage-track"
+                      role="progressbar"
+                      aria-label="CPU 使用率"
+                      aria-valuemin="0"
+                      aria-valuemax="100"
+                      :aria-valuenow="normalizeUsage(node.cpu)"
+                    >
+                      <span
+                        :class="['usage-fill', usageTone(node.cpu)]"
+                        :style="{ width: `${normalizeUsage(node.cpu)}%` }"
+                      ></span>
+                    </span>
+                    <span class="usage-value mono">{{ normalizeUsage(node.cpu) }}%</span>
+                  </div>
                 </template>
                 <span v-else class="text-dim">-</span>
               </td>
@@ -112,6 +142,18 @@ const businessLineNodes = computed(() => {
   return nodes.value.filter((node) => node.cluster === selectedCluster.value)
 })
 
+function normalizeUsage(value: number) {
+  if (!Number.isFinite(value)) return 0
+  return Math.min(100, Math.max(0, Math.round(value)))
+}
+
+function usageTone(value: number) {
+  const normalized = normalizeUsage(value)
+  if (normalized >= 90) return 'critical'
+  if (normalized >= 70) return 'warning'
+  return 'normal'
+}
+
 async function loadClusters() {
   const businessLineId = businessLineStore.current?.id
   if (!businessLineId) {
@@ -168,4 +210,50 @@ onMounted(loadClusters)
 .tag.biz {
   color: var(--text-mid);
 }
+
+.usage-cell {
+  width: max-content;
+  display: grid;
+  grid-template-columns: 112px 38px;
+  align-items: center;
+  gap: 10px;
+}
+
+.usage-track {
+  width: 112px;
+  height: 8px;
+  display: block;
+  overflow: hidden;
+  border: 1px solid var(--line-soft);
+  border-radius: 4px;
+  background: var(--bar-bg);
+  box-shadow: inset 0 1px 2px rgba(15, 23, 42, 0.06);
+}
+
+.usage-fill {
+  height: 100%;
+  display: block;
+  border-radius: 3px;
+  transition: width 240ms ease;
+}
+
+.usage-fill.normal {
+  background: #20a67a;
+}
+
+.usage-fill.warning {
+  background: var(--warn);
+}
+
+.usage-fill.critical {
+  background: var(--err);
+}
+
+.usage-value {
+  color: var(--text-mid);
+  font-size: 12px;
+  font-variant-numeric: tabular-nums;
+  text-align: right;
+  white-space: nowrap;
+}
 </style>

frontend/src/views/task/TaskCenter.vue

@@ -34,7 +34,12 @@
               <span :class="['task-status', task.status_class]">● {{ task.status_text }}</span>
               <span class="task-main">
                 <span class="task-name">{{ task.name }}</span>
-                <span class="task-runner mono">{{ task.runner }}</span>
+                <span class="task-meta">
+                  <span class="task-runner mono">{{ task.runner }}</span>
+                  <time class="task-time mono" :datetime="task.created_at" :title="formatTaskFullTime(task.created_at)">
+                    {{ formatTaskTime(task.created_at) }}
+                  </time>
+                </span>
               </span>
             </button>
           </div>
@@ -146,6 +151,33 @@ function formatTime(date: Date) {
   return date.toLocaleTimeString('zh-CN', { hour12: false })
 }
 
+function parseTaskTime(value: string) {
+  const date = new Date(value)
+  return Number.isNaN(date.getTime()) ? null : date
+}
+
+function formatTaskTime(value: string) {
+  const date = parseTaskTime(value)
+  if (!date) {
+    return '-'
+  }
+  return date.toLocaleString('zh-CN', {
+    month: '2-digit',
+    day: '2-digit',
+    hour: '2-digit',
+    minute: '2-digit',
+    second: '2-digit',
+    hour12: false,
+  }).replace('/', '-')
+}
+
+function formatTaskFullTime(value: string) {
+  const date = parseTaskTime(value)
+  return date
+    ? date.toLocaleString('zh-CN', { hour12: false })
+    : '时间未知'
+}
+
 watch(
   () => businessLineStore.current?.id,
   () => {
@@ -228,6 +260,14 @@ onMounted(() => {
   gap: 5px;
 }
 
+.task-meta {
+  min-width: 0;
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+}
+
 .task-name,
 .task-runner,
 .selected-name {
@@ -243,10 +283,18 @@ onMounted(() => {
 }
 
 .task-runner {
+  min-width: 0;
   color: var(--text-dim);
   font-size: 11px;
 }
 
+.task-time {
+  flex: none;
+  color: var(--text-dim);
+  font-size: 10.5px;
+  white-space: nowrap;
+}
+
 .task-log-panel .panel-head {
   gap: 14px;
 }