fix: 高峰倍率全链路透传、计费术语修正与边界处理

- 高峰倍率信息透传至可用渠道、支付计划、结算信息等 API，前端
  GroupBadge / GroupOptionItem / SubscriptionPlanCard / PaymentView /
  SubscriptionsView 统一展示高峰时段与倍率标签
- 修正计费术语："文本倍率" → "token 倍率"，明确高峰倍率同时作用于
  token 计费的图片 token，图片按次计费不受高峰影响
- 允许高峰倍率 multiplier=0，支持高峰时段免费策略
- 切换分组类型为 standard 时自动清除高峰倍率配置
- 长上下文计费与标准计费路径改用内部实现，移除冗余中间调用
- 前端高峰倍率相关控件文案改为 i18n
- 新增多组高峰倍率相关单元测试

frontend/src/components/common/GroupBadge.vue

@@ -20,6 +20,9 @@
         {{ labelText }}
       </template>
     </span>
+    <span v-if="hasPeakRate" :class="peakRateClass" :title="peakRateTitle">
+      {{ peakRateText }}
+    </span>
   </span>
 </template>
 
@@ -35,6 +38,10 @@ interface Props {
   subscriptionType?: SubscriptionType
   rateMultiplier?: number
   userRateMultiplier?: number | null // 用户专属倍率
+  peakRateEnabled?: boolean
+  peakStart?: string
+  peakEnd?: string
+  peakRateMultiplier?: number
   showRate?: boolean
   daysRemaining?: number | null // 剩余天数（订阅类型时使用）
   /**
@@ -50,6 +57,7 @@ const props = withDefaults(defineProps<Props>(), {
   showRate: true,
   daysRemaining: null,
   userRateMultiplier: null,
+  peakRateEnabled: false,
   alwaysShowRate: false
 })
 
@@ -67,6 +75,18 @@ const hasCustomRate = computed(() => {
   )
 })
 
+const hasPeakRate = computed(() => {
+  return Boolean(props.showRate && props.peakRateEnabled && props.peakStart && props.peakEnd)
+})
+
+const peakRateText = computed(() => {
+  return `${props.peakStart}-${props.peakEnd} ×${props.peakRateMultiplier ?? 1}`
+})
+
+const peakRateTitle = computed(() => {
+  return `高峰倍率：${peakRateText.value}`
+})
+
 // 是否显示右侧标签
 const showLabel = computed(() => {
   if (!props.showRate) return false
@@ -127,6 +147,10 @@ const labelClass = computed(() => {
   return `${base} bg-violet-200/60 text-violet-800 dark:bg-violet-800/40 dark:text-violet-300`
 })
 
+const peakRateClass = computed(() => {
+  return 'px-1.5 py-0.5 rounded text-[10px] font-semibold bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-300'
+})
+
 // Badge color based on platform and subscription type
 const badgeClass = computed(() => {
   if (props.platform === 'anthropic') {

frontend/src/components/common/GroupOptionItem.vue

@@ -24,16 +24,25 @@
 
     <!-- Right: rate pill + checkmark (vertically centered to first row) -->
     <div class="flex shrink-0 items-center gap-2 pt-0.5">
-      <!-- Rate pill (platform color) -->
-      <span v-if="rateMultiplier !== undefined" :class="['inline-flex items-center whitespace-nowrap rounded-full px-3 py-1 text-xs font-semibold', ratePillClass]">
-        <template v-if="hasCustomRate">
-          <span class="mr-1 line-through opacity-50">{{ rateMultiplier }}x</span>
-          <span class="font-bold">{{ userRateMultiplier }}x</span>
-        </template>
-        <template v-else>
-          {{ rateMultiplier }}x {{ t('admin.groups.rateLabel') }}
-        </template>
-      </span>
+      <div class="flex shrink-0 flex-col items-end gap-1">
+        <!-- Rate pill (platform color) -->
+        <span v-if="rateMultiplier !== undefined" :class="['inline-flex items-center whitespace-nowrap rounded-full px-3 py-1 text-xs font-semibold', ratePillClass]">
+          <template v-if="hasCustomRate">
+            <span class="mr-1 line-through opacity-50">{{ rateMultiplier }}x</span>
+            <span class="font-bold">{{ userRateMultiplier }}x</span>
+          </template>
+          <template v-else>
+            {{ rateMultiplier }}x {{ t('admin.groups.rateLabel') }}
+          </template>
+        </span>
+        <span
+          v-if="hasPeakRate"
+          class="inline-flex items-center whitespace-nowrap rounded-full bg-amber-50 px-3 py-1 text-xs font-semibold text-amber-700 dark:bg-amber-900/20 dark:text-amber-300"
+          :title="peakRateTitle"
+        >
+          {{ peakRateText }}
+        </span>
+      </div>
       <!-- Checkmark -->
       <svg
         v-if="showCheckmark && selected"
@@ -63,6 +72,10 @@ interface Props {
   subscriptionType?: SubscriptionType
   rateMultiplier?: number
   userRateMultiplier?: number | null
+  peakRateEnabled?: boolean
+  peakStart?: string
+  peakEnd?: string
+  peakRateMultiplier?: number
   description?: string | null
   selected?: boolean
   showCheckmark?: boolean
@@ -72,7 +85,8 @@ const props = withDefaults(defineProps<Props>(), {
   subscriptionType: 'standard',
   selected: false,
   showCheckmark: true,
-  userRateMultiplier: null
+  userRateMultiplier: null,
+  peakRateEnabled: false
 })
 
 // Whether user has a custom rate different from default
@@ -85,6 +99,18 @@ const hasCustomRate = computed(() => {
   )
 })
 
+const hasPeakRate = computed(() => {
+  return Boolean(props.peakRateEnabled && props.peakStart && props.peakEnd)
+})
+
+const peakRateText = computed(() => {
+  return `${props.peakStart}-${props.peakEnd} ×${props.peakRateMultiplier ?? 1}`
+})
+
+const peakRateTitle = computed(() => {
+  return `高峰倍率：${peakRateText.value}`
+})
+
 // Rate pill color matches platform badge color
 const ratePillClass = computed(() => {
   switch (props.platform) {