feat(计费): 支持账号计费倍率快照与统计展示

- 新增 accounts.rate_multiplier（默认 1.0，允许 0）
- 使用 usage_logs.account_rate_multiplier 记录倍率快照，避免历史回算
- 统计/导出/管理端展示账号口径费用（total_cost * account_rate_multiplier）

frontend/src/components/admin/account/AccountStatsModal.vue

@@ -61,11 +61,12 @@
             </p>
             <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
               {{ t('admin.accounts.stats.accumulatedCost') }}
-              <span class="text-gray-400 dark:text-gray-500"
-                >({{ t('admin.accounts.stats.standardCost') }}: ${{
+              <span class="text-gray-400 dark:text-gray-500">
+                ({{ t('usage.userBilled') }}: ${{ formatCost(stats.summary.total_user_cost) }} ·
+                {{ t('admin.accounts.stats.standardCost') }}: ${{
                   formatCost(stats.summary.total_standard_cost)
-                }})</span
-              >
+                }})
+              </span>
             </p>
           </div>
 
@@ -108,12 +109,15 @@
             <p class="text-2xl font-bold text-gray-900 dark:text-white">
               ${{ formatCost(stats.summary.avg_daily_cost) }}
             </p>
-            <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+             <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
               {{
                 t('admin.accounts.stats.basedOnActualDays', {
                   days: stats.summary.actual_days_used
                 })
               }}
+              <span class="text-gray-400 dark:text-gray-500">
+                ({{ t('usage.userBilled') }}: ${{ formatCost(stats.summary.avg_daily_user_cost) }})
+              </span>
             </p>
           </div>
 
@@ -164,13 +168,17 @@
             </div>
             <div class="space-y-2">
               <div class="flex items-center justify-between">
-                <span class="text-xs text-gray-500 dark:text-gray-400">{{
-                  t('admin.accounts.stats.cost')
-                }}</span>
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.accountBilled') }}</span>
                 <span class="text-sm font-semibold text-gray-900 dark:text-white"
                   >${{ formatCost(stats.summary.today?.cost || 0) }}</span
                 >
               </div>
+              <div class="flex items-center justify-between">
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.userBilled') }}</span>
+                <span class="text-sm font-semibold text-gray-900 dark:text-white"
+                  >${{ formatCost(stats.summary.today?.user_cost || 0) }}</span
+                >
+              </div>
               <div class="flex items-center justify-between">
                 <span class="text-xs text-gray-500 dark:text-gray-400">{{
                   t('admin.accounts.stats.requests')
@@ -210,13 +218,17 @@
                 }}</span>
               </div>
               <div class="flex items-center justify-between">
-                <span class="text-xs text-gray-500 dark:text-gray-400">{{
-                  t('admin.accounts.stats.cost')
-                }}</span>
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.accountBilled') }}</span>
                 <span class="text-sm font-semibold text-orange-600 dark:text-orange-400"
                   >${{ formatCost(stats.summary.highest_cost_day?.cost || 0) }}</span
                 >
               </div>
+              <div class="flex items-center justify-between">
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.userBilled') }}</span>
+                <span class="text-sm font-semibold text-gray-900 dark:text-white"
+                  >${{ formatCost(stats.summary.highest_cost_day?.user_cost || 0) }}</span
+                >
+              </div>
               <div class="flex items-center justify-between">
                 <span class="text-xs text-gray-500 dark:text-gray-400">{{
                   t('admin.accounts.stats.requests')
@@ -260,13 +272,17 @@
                 }}</span>
               </div>
               <div class="flex items-center justify-between">
-                <span class="text-xs text-gray-500 dark:text-gray-400">{{
-                  t('admin.accounts.stats.cost')
-                }}</span>
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.accountBilled') }}</span>
                 <span class="text-sm font-semibold text-gray-900 dark:text-white"
                   >${{ formatCost(stats.summary.highest_request_day?.cost || 0) }}</span
                 >
               </div>
+              <div class="flex items-center justify-between">
+                <span class="text-xs text-gray-500 dark:text-gray-400">{{ t('usage.userBilled') }}</span>
+                <span class="text-sm font-semibold text-gray-900 dark:text-white"
+                  >${{ formatCost(stats.summary.highest_request_day?.user_cost || 0) }}</span
+                >
+              </div>
             </div>
           </div>
         </div>
@@ -485,14 +501,24 @@ const trendChartData = computed(() => {
     labels: stats.value.history.map((h) => h.label),
     datasets: [
       {
-        label: t('admin.accounts.stats.cost') + ' (USD)',
-        data: stats.value.history.map((h) => h.cost),
+        label: t('usage.accountBilled') + ' (USD)',
+        data: stats.value.history.map((h) => h.actual_cost),
         borderColor: '#3b82f6',
         backgroundColor: 'rgba(59, 130, 246, 0.1)',
         fill: true,
         tension: 0.3,
         yAxisID: 'y'
       },
+      {
+        label: t('usage.userBilled') + ' (USD)',
+        data: stats.value.history.map((h) => h.user_cost),
+        borderColor: '#10b981',
+        backgroundColor: 'rgba(16, 185, 129, 0.08)',
+        fill: false,
+        tension: 0.3,
+        borderDash: [5, 5],
+        yAxisID: 'y'
+      },
       {
         label: t('admin.accounts.stats.requests'),
         data: stats.value.history.map((h) => h.requests),
@@ -570,7 +596,7 @@ const lineChartOptions = computed(() => ({
       },
       title: {
         display: true,
-        text: t('admin.accounts.stats.cost') + ' (USD)',
+        text: t('usage.accountBilled') + ' (USD)',
         color: '#3b82f6',
         font: {
           size: 11

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

@@ -27,9 +27,18 @@
       </div>
       <div class="min-w-0 flex-1">
         <p class="text-xs font-medium text-gray-500">{{ t('usage.totalCost') }}</p>
-        <p class="text-xl font-bold text-green-600">${{ (stats?.total_actual_cost || 0).toFixed(4) }}</p>
-        <p class="text-xs text-gray-400">
-          {{ t('usage.standardCost') }}: <span class="line-through">${{ (stats?.total_cost || 0).toFixed(4) }}</span>
+        <p class="text-xl font-bold text-green-600">
+          ${{ ((stats?.total_account_cost ?? stats?.total_actual_cost) || 0).toFixed(4) }}
+        </p>
+        <p class="text-xs text-gray-400" v-if="stats?.total_account_cost != null">
+          {{ t('usage.userBilled') }}:
+          <span class="text-gray-300">${{ (stats?.total_actual_cost || 0).toFixed(4) }}</span>
+          · {{ t('usage.standardCost') }}:
+          <span class="text-gray-300">${{ (stats?.total_cost || 0).toFixed(4) }}</span>
+        </p>
+        <p class="text-xs text-gray-400" v-else>
+          {{ t('usage.standardCost') }}:
+          <span class="line-through">${{ (stats?.total_cost || 0).toFixed(4) }}</span>
         </p>
       </div>
     </div>

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

@@ -81,18 +81,23 @@
         </template>
 
         <template #cell-cost="{ row }">
-          <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 class="text-sm">
+            <div class="flex items-center gap-1.5">
+              <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>
+            <div v-if="row.account_rate_multiplier != null" class="mt-0.5 text-[11px] text-gray-400">
+              A ${{ (row.total_cost * row.account_rate_multiplier).toFixed(6) }}
+            </div>
           </div>
         </template>
 
@@ -202,14 +207,24 @@
             <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.accountMultiplier') }}</span>
+            <span class="font-semibold text-blue-400">{{ (tooltipData?.account_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">${{ tooltipData?.total_cost?.toFixed(6) || '0.000000' }}</span>
           </div>
-          <div class="flex items-center justify-between gap-6 border-t border-gray-700 pt-1.5">
-            <span class="text-gray-400">{{ t('usage.billed') }}</span>
+          <div class="flex items-center justify-between gap-6">
+            <span class="text-gray-400">{{ t('usage.userBilled') }}</span>
             <span class="font-semibold text-green-400">${{ tooltipData?.actual_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.accountBilled') }}</span>
+            <span class="font-semibold text-green-400">
+              ${{ (((tooltipData?.total_cost || 0) * (tooltipData?.account_rate_multiplier ?? 1)) || 0).toFixed(6) }}
+            </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>