fix(前端): 修复 ESLint 代码规范问题

- 修复 AccountTableFilters.vue 中的 vue/no-mutating-props 错误，使用 emit 模式替代直接修改 props
- 修复 TypeScript 类型错误，支持 Select 组件的 null 值类型
- 为所有空 catch 块添加错误日志，提升代码可维护性和调试能力
- 涉及文件：AccountTableFilters.vue, UserAllowedGroupsModal.vue, UserApiKeysModal.vue, UserBalanceModal.vue, AccountsView.vue, UsageView.vue, DashboardView.vue, ProfileView.vue

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/components/admin/user/UserBalanceModal.vue

@@ -41,6 +41,6 @@ const handleBalanceSubmit = async () => {
   try {
     await adminAPI.users.updateBalance(props.user.id, form.amount, props.operation, form.notes)
     appStore.showSuccess(t('common.success')); emit('success'); emit('close')
-  } catch {} finally { submitting.value = false }
+  } catch (error) { console.error('Failed to update balance:', error) } finally { submitting.value = false }
 }
 </script>