feat(admin/usage): 优化管理员用量页面功能和体验

后端改进：
- 新增 GetStatsWithFilters 方法支持完整筛选条件
- Stats 端点支持 account_id, group_id, model, stream, billing_type 参数
- 统一使用 filters 结构体，移除冗余的分支逻辑

前端改进：
- 统计卡片添加"所选范围内"文字提示
- 优化总消费显示格式，清晰展示实际费用和标准计费
- Token 和费用列添加问号图标 tooltip 显示详细信息
- API Key 搜索框体验优化：点击即显示下拉选项
- 选择用户后自动加载该用户的所有 API Key

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

@@ -44,32 +44,56 @@
             <span class="text-gray-400">({{ row.image_size || '2K' }})</span>
           </div>
           <!-- Token 请求 -->
-          <div v-else class="space-y-1 text-sm">
-            <div class="flex items-center gap-2">
-              <div class="inline-flex items-center gap-1">
-                <Icon name="arrowDown" size="sm" class="h-3.5 w-3.5 text-emerald-500" />
-                <span class="font-medium text-gray-900 dark:text-white">{{ row.input_tokens?.toLocaleString() || 0 }}</span>
+          <div v-else class="flex items-center gap-1.5">
+            <div class="space-y-1 text-sm">
+              <div class="flex items-center gap-2">
+                <div class="inline-flex items-center gap-1">
+                  <Icon name="arrowDown" size="sm" class="h-3.5 w-3.5 text-emerald-500" />
+                  <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">
+                  <Icon name="arrowUp" size="sm" class="h-3.5 w-3.5 text-violet-500" />
+                  <span class="font-medium text-gray-900 dark:text-white">{{ row.output_tokens?.toLocaleString() || 0 }}</span>
+                </div>
               </div>
-              <div class="inline-flex items-center gap-1">
-                <Icon name="arrowUp" size="sm" class="h-3.5 w-3.5 text-violet-500" />
-                <span class="font-medium text-gray-900 dark:text-white">{{ row.output_tokens?.toLocaleString() || 0 }}</span>
+              <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>
-            <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>
+            <!-- Token Detail Tooltip -->
+            <div
+              class="group relative"
+              @mouseenter="showTokenTooltip($event, row)"
+              @mouseleave="hideTokenTooltip"
+            >
+              <div class="flex h-4 w-4 cursor-help items-center justify-center rounded-full bg-gray-100 transition-colors group-hover:bg-blue-100 dark:bg-gray-700 dark:group-hover:bg-blue-900/50">
+                <Icon name="infoCircle" size="xs" class="text-gray-400 group-hover:text-blue-500 dark:text-gray-500 dark:group-hover:text-blue-400" />
               </div>
             </div>
           </div>
         </template>
 
         <template #cell-cost="{ row }">
-          <span class="font-medium text-green-600 dark:text-green-400">${{ row.actual_cost?.toFixed(6) || '0.000000' }}</span>
+          <div class="flex items-center gap-1.5 text-sm">
+            <span class="font-medium text-green-600 dark:text-green-400">${{ row.actual_cost?.toFixed(6) || '0.000000' }}</span>
+            <!-- Cost Detail Tooltip -->
+            <div
+              class="group relative"
+              @mouseenter="showTooltip($event, row)"
+              @mouseleave="hideTooltip"
+            >
+              <div class="flex h-4 w-4 cursor-help items-center justify-center rounded-full bg-gray-100 transition-colors group-hover:bg-blue-100 dark:bg-gray-700 dark:group-hover:bg-blue-900/50">
+                <Icon name="infoCircle" size="xs" class="text-gray-400 group-hover:text-blue-500 dark:text-gray-500 dark:group-hover:text-blue-400" />
+              </div>
+            </div>
+          </div>
         </template>
 
         <template #cell-billing_type="{ row }">
@@ -106,6 +130,77 @@
       </DataTable>
     </div>
   </div>
+
+  <!-- Token Tooltip Portal -->
+  <Teleport to="body">
+    <div
+      v-if="tokenTooltipVisible"
+      class="fixed z-[9999] pointer-events-none -translate-y-1/2"
+      :style="{
+        left: tokenTooltipPosition.x + 'px',
+        top: tokenTooltipPosition.y + 'px'
+      }"
+    >
+      <div class="whitespace-nowrap rounded-lg border border-gray-700 bg-gray-900 px-3 py-2.5 text-xs text-white shadow-xl dark:border-gray-600 dark:bg-gray-800">
+        <div class="space-y-1.5">
+          <div class="mb-2 border-b border-gray-700 pb-1.5">
+            <div class="text-xs font-semibold text-gray-300 mb-1">Token {{ t('usage.details') }}</div>
+            <div v-if="tokenTooltipData && tokenTooltipData.input_tokens > 0" class="flex items-center justify-between gap-4">
+              <span class="text-gray-400">{{ t('admin.usage.inputTokens') }}</span>
+              <span class="font-medium text-white">{{ tokenTooltipData.input_tokens.toLocaleString() }}</span>
+            </div>
+            <div v-if="tokenTooltipData && tokenTooltipData.output_tokens > 0" class="flex items-center justify-between gap-4">
+              <span class="text-gray-400">{{ t('admin.usage.outputTokens') }}</span>
+              <span class="font-medium text-white">{{ tokenTooltipData.output_tokens.toLocaleString() }}</span>
+            </div>
+            <div v-if="tokenTooltipData && tokenTooltipData.cache_creation_tokens > 0" class="flex items-center justify-between gap-4">
+              <span class="text-gray-400">{{ t('admin.usage.cacheCreationTokens') }}</span>
+              <span class="font-medium text-white">{{ tokenTooltipData.cache_creation_tokens.toLocaleString() }}</span>
+            </div>
+            <div v-if="tokenTooltipData && tokenTooltipData.cache_read_tokens > 0" class="flex items-center justify-between gap-4">
+              <span class="text-gray-400">{{ t('admin.usage.cacheReadTokens') }}</span>
+              <span class="font-medium text-white">{{ tokenTooltipData.cache_read_tokens.toLocaleString() }}</span>
+            </div>
+          </div>
+          <div class="flex items-center justify-between gap-6 border-t border-gray-700 pt-1.5">
+            <span class="text-gray-400">{{ t('usage.totalTokens') }}</span>
+            <span class="font-semibold text-blue-400">{{ ((tokenTooltipData?.input_tokens || 0) + (tokenTooltipData?.output_tokens || 0) + (tokenTooltipData?.cache_creation_tokens || 0) + (tokenTooltipData?.cache_read_tokens || 0)).toLocaleString() }}</span>
+          </div>
+        </div>
+        <div class="absolute right-full top-1/2 h-0 w-0 -translate-y-1/2 border-b-[6px] border-r-[6px] border-t-[6px] border-b-transparent border-r-gray-900 border-t-transparent dark:border-r-gray-800"></div>
+      </div>
+    </div>
+  </Teleport>
+
+  <!-- Cost Tooltip Portal -->
+  <Teleport to="body">
+    <div
+      v-if="tooltipVisible"
+      class="fixed z-[9999] pointer-events-none -translate-y-1/2"
+      :style="{
+        left: tooltipPosition.x + 'px',
+        top: tooltipPosition.y + 'px'
+      }"
+    >
+      <div class="whitespace-nowrap rounded-lg border border-gray-700 bg-gray-900 px-3 py-2.5 text-xs text-white shadow-xl dark:border-gray-600 dark:bg-gray-800">
+        <div class="space-y-1.5">
+          <div class="flex items-center justify-between gap-6">
+            <span class="text-gray-400">{{ t('usage.rate') }}</span>
+            <span class="font-semibold text-blue-400">{{ (tooltipData?.rate_multiplier || 1).toFixed(2) }}x</span>
+          </div>
+          <div class="flex items-center justify-between gap-6">
+            <span class="text-gray-400">{{ t('usage.original') }}</span>
+            <span class="font-medium text-white">${{ tooltipData?.total_cost?.toFixed(6) || '0.000000' }}</span>
+          </div>
+          <div class="flex items-center justify-between gap-6 border-t border-gray-700 pt-1.5">
+            <span class="text-gray-400">{{ t('usage.billed') }}</span>
+            <span class="font-semibold text-green-400">${{ tooltipData?.actual_cost?.toFixed(6) || '0.000000' }}</span>
+          </div>
+        </div>
+        <div class="absolute right-full top-1/2 h-0 w-0 -translate-y-1/2 border-b-[6px] border-r-[6px] border-t-[6px] border-b-transparent border-r-gray-900 border-t-transparent dark:border-r-gray-800"></div>
+      </div>
+    </div>
+  </Teleport>
 </template>
 
 <script setup lang="ts">
@@ -116,12 +211,23 @@ import { useAppStore } from '@/stores/app'
 import DataTable from '@/components/common/DataTable.vue'
 import EmptyState from '@/components/common/EmptyState.vue'
 import Icon from '@/components/icons/Icon.vue'
+import type { UsageLog } from '@/types'
 
 defineProps(['data', 'loading'])
 const { t } = useI18n()
 const appStore = useAppStore()
 const copiedRequestId = ref<string | null>(null)
 
+// Tooltip state - cost
+const tooltipVisible = ref(false)
+const tooltipPosition = ref({ x: 0, y: 0 })
+const tooltipData = ref<UsageLog | null>(null)
+
+// Tooltip state - token
+const tokenTooltipVisible = ref(false)
+const tokenTooltipPosition = ref({ x: 0, y: 0 })
+const tokenTooltipData = ref<UsageLog | null>(null)
+
 const cols = computed(() => [
   { key: 'user', label: t('admin.usage.user'), sortable: false },
   { key: 'api_key', label: t('usage.apiKeyFilter'), sortable: false },
@@ -160,4 +266,34 @@ const copyRequestId = async (requestId: string) => {
     appStore.showError(t('common.copyFailed'))
   }
 }
+
+// Cost tooltip functions
+const showTooltip = (event: MouseEvent, row: UsageLog) => {
+  const target = event.currentTarget as HTMLElement
+  const rect = target.getBoundingClientRect()
+  tooltipData.value = row
+  tooltipPosition.value.x = rect.right + 8
+  tooltipPosition.value.y = rect.top + rect.height / 2
+  tooltipVisible.value = true
+}
+
+const hideTooltip = () => {
+  tooltipVisible.value = false
+  tooltipData.value = null
+}
+
+// Token tooltip functions
+const showTokenTooltip = (event: MouseEvent, row: UsageLog) => {
+  const target = event.currentTarget as HTMLElement
+  const rect = target.getBoundingClientRect()
+  tokenTooltipData.value = row
+  tokenTooltipPosition.value.x = rect.right + 8
+  tokenTooltipPosition.value.y = rect.top + rect.height / 2
+  tokenTooltipVisible.value = true
+}
+
+const hideTokenTooltip = () => {
+  tokenTooltipVisible.value = false
+  tokenTooltipData.value = null
+}
 </script>