fix(admin,api): 上分超额提示而非静默截断，并返回中文业务错误

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/admin/src/views/Agents.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { ref, onMounted } from 'vue';
 import { useAdminLocale } from '../composables/useAdminLocale';
-import { resolveFormError } from '../i18n/form-validation';
+import { resolveFormError, resolveApiError } from '../i18n/form-validation';
 import api from '../api';
 
 const { t } = useAdminLocale();
@@ -27,6 +27,7 @@ import AdminTableEmpty from '../components/AdminTableEmpty.vue';
 import AgentCreditContext from '../components/AgentCreditContext.vue';
 import {
   fetchAdminAgentCreditContext,
+  maxCreditIncreaseAmount,
   type AgentCreditAdjustContext,
 } from '../utils/agent-credit-context';
 
@@ -201,6 +202,11 @@ async function submitCredit() {
     ElMessage.warning(t('msg.credit_zero'));
     return;
   }
+  const maxInc = maxCreditIncreaseAmount(creditContext.value);
+  if (creditForm.value.amount > 0 && maxInc !== undefined && creditForm.value.amount > maxInc) {
+    ElMessage.warning(t('err.insufficient_credit'));
+    return;
+  }
   creditLoading.value = true;
   try {
     await api.post(`/admin/agents/${editingId.value}/credit`, {
@@ -212,8 +218,7 @@ async function submitCredit() {
     creditVisible.value = false;
     load();
   } catch (e: unknown) {
-    const err = e as { response?: { data?: { error?: string } } };
-    ElMessage.error(err.response?.data?.error ?? t('msg.credit_adjust_failed'));
+    ElMessage.error(resolveApiError(e, t, 'msg.credit_adjust_failed'));
   } finally {
     creditLoading.value = false;
   }