fix(frontend): 恢复 UsageTable 缺失的列和功能

- 恢复 API Key、账号、分组、类型、计费类型等列
- 恢复 Token 详情显示（含缓存读写）
- 恢复首Token时间、耗时列
- 恢复请求ID列及复制功能

frontend/src/components/admin/usage/UsageTable.vue

 <template>
-  <div class="card overflow-hidden"><div class="overflow-auto">
-    <DataTable :columns="cols" :data="data" :loading="loading">
-      <template #cell-user="{ row }"><div class="text-sm"><span class="font-medium text-gray-900 dark:text-white">{{ row.user?.email || '-' }}</span><span class="ml-1 text-xs text-gray-400">#{{ row.user_id }}</span></div></template>
-      <template #cell-model="{ value }"><span class="font-medium">{{ value }}</span></template>
-      <template #cell-tokens="{ row }"><div class="text-sm">In: {{ row.input_tokens.toLocaleString() }} / Out: {{ row.output_tokens.toLocaleString() }}</div></template>
-      <template #cell-cost="{ row }"><span class="font-medium text-green-600">${{ row.actual_cost.toFixed(6) }}</span></template>
-      <template #cell-created_at="{ value }"><span class="text-sm text-gray-500">{{ formatDateTime(value) }}</span></template>
-      <template #empty><EmptyState :message="t('usage.noRecords')" /></template>
-    </DataTable>
-  </div></div>
+  <div class="card overflow-hidden">
+    <div class="overflow-auto">
+      <DataTable :columns="cols" :data="data" :loading="loading">
+        <template #cell-user="{ row }">
+          <div class="text-sm">
+            <span class="font-medium text-gray-900 dark:text-white">{{ row.user?.email || '-' }}</span>
+            <span class="ml-1 text-gray-500 dark:text-gray-400">#{{ row.user_id }}</span>
+          </div>
+        </template>
+
+        <template #cell-api_key="{ row }">
+          <span class="text-sm text-gray-900 dark:text-white">{{ row.api_key?.name || '-' }}</span>
+        </template>
+
+        <template #cell-account="{ row }">
+          <span class="text-sm text-gray-900 dark:text-white">{{ row.account?.name || '-' }}</span>
+        </template>
+
+        <template #cell-model="{ value }">
+          <span class="font-medium text-gray-900 dark:text-white">{{ value }}</span>
+        </template>
+
+        <template #cell-group="{ row }">
+          <span v-if="row.group" class="inline-flex items-center rounded px-2 py-0.5 text-xs font-medium bg-indigo-100 text-indigo-800 dark:bg-indigo-900 dark:text-indigo-200">
+            {{ row.group.name }}
+          </span>
+          <span v-else class="text-sm text-gray-400 dark:text-gray-500">-</span>
+        </template>
+
+        <template #cell-stream="{ row }">
+          <span class="inline-flex items-center rounded px-2 py-0.5 text-xs font-medium" :class="row.stream ? 'bg-blue-100 text-blue-800 dark:bg-blue-900 dark:text-blue-200' : 'bg-gray-100 text-gray-800 dark:bg-gray-700 dark:text-gray-200'">
+            {{ row.stream ? t('usage.stream') : t('usage.sync') }}
+          </span>
+        </template>
+
+        <template #cell-tokens="{ row }">
+          <div class="space-y-1 text-sm">
+            <div class="flex items-center gap-2">
+              <div class="inline-flex items-center gap-1">
+                <svg class="h-3.5 w-3.5 text-emerald-500" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 14l-7 7m0 0l-7-7m7 7V3" /></svg>
+                <span class="font-medium text-gray-900 dark:text-white">{{ row.input_tokens?.toLocaleString() || 0 }}</span>
+              </div>
+              <div class="inline-flex items-center gap-1">
+                <svg class="h-3.5 w-3.5 text-violet-500" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M5 10l7-7m0 0l7 7m-7-7v18" /></svg>
+                <span class="font-medium text-gray-900 dark:text-white">{{ row.output_tokens?.toLocaleString() || 0 }}</span>
+              </div>
+            </div>
+            <div v-if="row.cache_read_tokens > 0 || row.cache_creation_tokens > 0" class="flex items-center gap-2">
+              <div v-if="row.cache_read_tokens > 0" class="inline-flex items-center gap-1">
+                <svg class="h-3.5 w-3.5 text-sky-500" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M5 8h14M5 8a2 2 0 110-4h14a2 2 0 110 4M5 8v10a2 2 0 002 2h10a2 2 0 002-2V8m-9 4h4" /></svg>
+                <span class="font-medium text-sky-600 dark:text-sky-400">{{ formatCacheTokens(row.cache_read_tokens) }}</span>
+              </div>
+              <div v-if="row.cache_creation_tokens > 0" class="inline-flex items-center gap-1">
+                <svg class="h-3.5 w-3.5 text-amber-500" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" /></svg>
+                <span class="font-medium text-amber-600 dark:text-amber-400">{{ formatCacheTokens(row.cache_creation_tokens) }}</span>
+              </div>
+            </div>
+          </div>
+        </template>
+
+        <template #cell-cost="{ row }">
+          <span class="font-medium text-green-600 dark:text-green-400">${{ row.actual_cost?.toFixed(6) || '0.000000' }}</span>
+        </template>
+
+        <template #cell-billing_type="{ row }">
+          <span class="inline-flex items-center rounded px-2 py-0.5 text-xs font-medium" :class="row.billing_type === 1 ? 'bg-purple-100 text-purple-800 dark:bg-purple-900 dark:text-purple-200' : 'bg-emerald-100 text-emerald-800 dark:bg-emerald-900 dark:text-emerald-200'">
+            {{ row.billing_type === 1 ? t('usage.subscription') : t('usage.balance') }}
+          </span>
+        </template>
+
+        <template #cell-first_token="{ row }">
+          <span v-if="row.first_token_ms != null" class="text-sm text-gray-600 dark:text-gray-400">{{ formatDuration(row.first_token_ms) }}</span>
+          <span v-else class="text-sm text-gray-400 dark:text-gray-500">-</span>
+        </template>
+
+        <template #cell-duration="{ row }">
+          <span class="text-sm text-gray-600 dark:text-gray-400">{{ formatDuration(row.duration_ms) }}</span>
+        </template>
+
+        <template #cell-created_at="{ value }">
+          <span class="text-sm text-gray-600 dark:text-gray-400">{{ formatDateTime(value) }}</span>
+        </template>
+
+        <template #cell-request_id="{ row }">
+          <div v-if="row.request_id" class="flex items-center gap-1.5 max-w-[120px]">
+            <span class="font-mono text-xs text-gray-500 dark:text-gray-400 truncate" :title="row.request_id">{{ row.request_id }}</span>
+            <button @click="copyRequestId(row.request_id)" class="flex-shrink-0 rounded p-0.5 transition-colors hover:bg-gray-100 dark:hover:bg-dark-700" :class="copiedRequestId === row.request_id ? 'text-green-500' : 'text-gray-400 hover:text-gray-600 dark:hover:text-gray-300'" :title="copiedRequestId === row.request_id ? t('keys.copied') : t('keys.copyToClipboard')">
+              <svg v-if="copiedRequestId === row.request_id" class="h-3.5 w-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24" stroke-width="2"><path stroke-linecap="round" stroke-linejoin="round" d="M5 13l4 4L19 7" /></svg>
+              <svg v-else class="h-3.5 w-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24" stroke-width="2"><path stroke-linecap="round" stroke-linejoin="round" d="M8 16H6a2 2 0 01-2-2V6a2 2 0 012-2h8a2 2 0 012 2v2m-6 12h8a2 2 0 002-2v-8a2 2 0 00-2-2h-8a2 2 0 00-2 2v8a2 2 0 002 2z" /></svg>
+            </button>
+          </div>
+          <span v-else class="text-gray-400 dark:text-gray-500">-</span>
+        </template>
+
+        <template #empty><EmptyState :message="t('usage.noRecords')" /></template>
+      </DataTable>
+    </div>
+  </div>
 </template>
 
 <script setup lang="ts">
-import { computed } from 'vue'; import { useI18n } from 'vue-i18n'; import { formatDateTime } from '@/utils/format'; import DataTable from '@/components/common/DataTable.vue'; import EmptyState from '@/components/common/EmptyState.vue'
-defineProps(['data', 'loading']); const { t } = useI18n()
+import { ref, computed } from 'vue'
+import { useI18n } from 'vue-i18n'
+import { formatDateTime } from '@/utils/format'
+import { useAppStore } from '@/stores/app'
+import DataTable from '@/components/common/DataTable.vue'
+import EmptyState from '@/components/common/EmptyState.vue'
+
+defineProps(['data', 'loading'])
+const { t } = useI18n()
+const appStore = useAppStore()
+const copiedRequestId = ref<string | null>(null)
+
 const cols = computed(() => [
-  { key: 'user', label: t('admin.usage.user') }, { key: 'model', label: t('usage.model'), sortable: true },
-  { key: 'tokens', label: t('usage.tokens') }, { key: 'cost', label: t('usage.cost') },
-  { key: 'created_at', label: t('usage.time'), sortable: true }
+  { key: 'user', label: t('admin.usage.user'), sortable: false },
+  { key: 'api_key', label: t('usage.apiKeyFilter'), sortable: false },
+  { key: 'account', label: t('admin.usage.account'), sortable: false },
+  { key: 'model', label: t('usage.model'), sortable: true },
+  { key: 'group', label: t('admin.usage.group'), sortable: false },
+  { key: 'stream', label: t('usage.type'), sortable: false },
+  { key: 'tokens', label: t('usage.tokens'), sortable: false },
+  { key: 'cost', label: t('usage.cost'), sortable: false },
+  { key: 'billing_type', label: t('usage.billingType'), sortable: false },
+  { key: 'first_token', label: t('usage.firstToken'), sortable: false },
+  { key: 'duration', label: t('usage.duration'), sortable: false },
+  { key: 'created_at', label: t('usage.time'), sortable: true },
+  { key: 'request_id', label: t('admin.usage.requestId'), sortable: false }
 ])
-</script>
+
\ No newline at end of file
+const formatCacheTokens = (tokens: number): string => {
+  if (tokens >= 1000000) return `${(tokens / 1000000).toFixed(1)}M`
+  if (tokens >= 1000) return `${(tokens / 1000).toFixed(1)}K`
+  return tokens.toString()
+}
+
+const formatDuration = (ms: number | null | undefined): string => {
+  if (ms == null) return '-'
+  if (ms < 1000) return `${ms}ms`
+  return `${(ms / 1000).toFixed(2)}s`
+}
+
+const copyRequestId = async (requestId: string) => {
+  try {
+    await navigator.clipboard.writeText(requestId)
+    copiedRequestId.value = requestId
+    appStore.showSuccess(t('admin.usage.requestIdCopied'))
+    setTimeout(() => { copiedRequestId.value = null }, 2000)
+  } catch {
+    appStore.showError(t('common.copyFailed'))
+  }
+}
+</script>