refactor: 将 @iconify/vue 图标替换为 lucide-vue-next 本地组件

- 所有 lucide: 前缀的图标字符串替换为 lucide-vue-next 组件直接引用
- 动态图标绑定改为 <component :is> 渲染
- h(Icon, { icon: 'lucide:xxx' }) 改为 h(Xxx, { class: ... })
- app-card.vue 的 icon_url 改为 <img> 标签（实际是图片路径）
- 修复 Webhook 标识符冲突（重命名为 WebhookIcon）
- payment-channels 保留 @iconify/vue 用于品牌图标（支付宝、微信、Stripe、PayPal、USDT）

frontend/src/pages/agent/finance/index.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { Icon } from '@iconify/vue'
+import { ArrowDownLeft, ArrowUpRight, Loader2, Receipt, RotateCcw } from 'lucide-vue-next'
 import { onMounted, ref } from 'vue'
 
 import api from '@/services/api'
@@ -86,11 +86,11 @@ function getTypeClass(type: string) {
       </UiCardHeader>
       <UiCardContent class="p-0">
         <div v-if="loading" class="flex items-center justify-center py-12">
-          <Icon icon="lucide:loader-2" class="size-8 animate-spin text-muted-foreground" />
+          <Loader2 class="size-8 animate-spin text-muted-foreground" />
         </div>
 
         <div v-else-if="transactions.length === 0" class="text-center py-12 text-muted-foreground">
-          <Icon icon="lucide:receipt" class="size-16 mx-auto mb-4 opacity-30" />
+          <Receipt class="size-16 mx-auto mb-4 opacity-30" />
           <p>暂无交易记录</p>
         </div>
 
@@ -105,8 +105,8 @@ function getTypeClass(type: string) {
                 class="size-10 rounded-xl flex items-center justify-center"
                 :class="tx.type === 'recharge' ? 'bg-green-500/10' : tx.type === 'refund' ? 'bg-blue-500/10' : 'bg-red-500/10'"
               >
-                <Icon
-                  :icon="tx.type === 'recharge' ? 'lucide:arrow-down-left' : tx.type === 'refund' ? 'lucide:rotate-ccw' : 'lucide:arrow-up-right'"
+                <component
+                  :is="tx.type === 'recharge' ? ArrowDownLeft : tx.type === 'refund' ? RotateCcw : ArrowUpRight"
                   :class="getTypeClass(tx.type)"
                   class="size-5"
                 />