fix: 修复代理生成卡密权限检查和参数问题

- 后端兼容application_id和app_id参数
- 添加卡类权限检查，确保代理只能生成有权限的卡类
- 前端使用application_id参数名
- 移除卡类显示中的billing_type原始值，改为显示价格

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/pages/agent/cards/create.vue

@@ -104,7 +104,7 @@ async function handleGenerate() {
   saving.value = true
   try {
     const data = await api.post<{ codes: string[], cards: any[] }>('/agent/cards/generate', {
-      app_id: Number(form.value.application_id),
+      application_id: Number(form.value.application_id),
       card_type_id: Number(form.value.card_type_id),
       quantity: form.value.count,
     })
@@ -178,7 +178,7 @@ onMounted(() => {
                   </UiSelectTrigger>
                   <UiSelectContent>
                     <UiSelectItem v-for="type in cardTypes" :key="type.id" :value="String(type.id)">
-                      {{ type.name }}<template v-if="type.billing_type"> ({{ type.billing_type }})</template>
+                      {{ type.name }} - ¥{{ type.price }}
                     </UiSelectItem>
                   </UiSelectContent>
                 </UiSelect>