feat(排产单): 新增只读模式并优化导出功能

添加只读视图组件 read.vue，修改 detail.vue 和 index.vue 以支持 readonly 属性
将导出按钮移至行操作列并支持单行导出
优化排产日期列宽度和操作列布局

klp-ui/src/views/aps/planSheet/PlanDetailForm.vue

@@ -1,5 +1,5 @@
 <template>
-  <el-form ref="form" :model="formData" :rules="rules" label-width="60px">
+  <el-form ref="form" :model="formData" :rules="rules" label-width="60px" :disabled="readonly">
     <el-collapse v-model="activeNames" :accordion="false">
       <!-- 订单信息组 -->
       <el-collapse-item title="订单信息" name="1">
@@ -195,6 +195,10 @@ export default {
     planSheetId: {
       type: String,
       required: true
+    },
+    readonly: {
+      type: Boolean,
+      default: false
     }
   },
   computed: {