style(business): 统一优化多个业务弹窗为接近全屏高度

- /business/waybill-manage 新增/编辑弹窗添加 dialogCustomClass 控制高度样式，覆盖默认 max-height 限制
- /business/contract-manage 弹窗同样加 dialogCustomClass，scoped 样式解开 Avue 弹窗默认 body 高度限制并实现底部操作栏粘性
- element-ui.scss 新增对应页 dialog 样式，确保弹窗上下留白20px，内容区高度自动适应，底部操作栏始终可见
- 复用 business-crud-page 组件中传入 option 的 dialogCustomClass 实现页面隔离样式，不影响其他业务

src/option/business/contract-manage.js

@@ -622,3 +622,4 @@ option.dialogWidth = 1480;
 option.dialogTop = '4vh';
 option.dialogCloseBtn = true;
 option.menuWidth = 320;
+option.dialogCustomClass = 'contract-manage-dialog';

src/option/business/waybill-manage.js

@@ -323,6 +323,7 @@ export const config = {
 };
 
 export const option = {
+  dialogCustomClass: 'waybill-manage-dialog',
   ...createCrudOption(
     withSearchPlaceholders([
       {