feat: 新增售后异议管理全流程功能

本次提交完成售后异议管理模块的开发，主要包括以下内容：
1. 新增售后异议主页面、待办页面和意见填写页面
2. 新增5个通用业务组件用于页面渲染
3. 新增4个业务API接口文件
4. 优化流程图表单描述、文件列表样式和钢卷信息展示
5. 完善投诉受理单的日期格式化和实体类继承

klp-ui/src/views/wms/post/objection/components/HandlingSchemeSection.vue

@@ -0,0 +1,102 @@
+<template>
+  <div v-if="enabled" class="section-container">
+    <div class="section-title">
+      <span>处理方案</span>
+      <el-button v-if="editable && !editing" size="mini" type="text" icon="el-icon-edit" @click="startEdit">编辑</el-button>
+      <template v-if="editing">
+        <el-button size="mini" type="text" icon="el-icon-check" @click="handleSave">保存</el-button>
+        <el-button size="mini" type="text" icon="el-icon-close" @click="cancelEdit">取消</el-button>
+      </template>
+    </div>
+    <div v-if="editing">
+      <editor v-model="editContent" :min-height="200" />
+    </div>
+    <div v-else>
+      <div v-if="content" class="plan-content" v-html="content"></div>
+      <div v-else class="empty-data">暂无处理方案</div>
+    </div>
+  </div>
+</template>
+
+<script>
+export default {
+  name: 'HandlingSchemeSection',
+  props: {
+    enabled: {
+      type: Boolean,
+      default: true
+    },
+    editable: {
+      type: Boolean,
+      default: false
+    },
+    content: {
+      type: String,
+      default: ''
+    }
+  },
+  data() {
+    return {
+      editing: false,
+      editContent: ''
+    };
+  },
+  watch: {
+    content(val) {
+      if (!this.editing) {
+        this.editContent = val || '';
+      }
+    }
+  },
+  methods: {
+    startEdit() {
+      this.editContent = this.content || '';
+      this.editing = true;
+    },
+    cancelEdit() {
+      this.editing = false;
+      this.editContent = '';
+    },
+    handleSave() {
+      if (!this.editContent) {
+        this.$modal.msgWarning('请输入处理方案');
+        return;
+      }
+      this.$emit('save', this.editContent);
+      this.editing = false;
+    }
+  }
+}
+</script>
+
+<style scoped>
+.section-title {
+  width: 100%;
+  font-size: 15px;
+  font-weight: 600;
+  color: #1d2129;
+  margin: 20px 0 12px 0;
+  padding: 0 0 10px 0;
+  border-bottom: 2px solid transparent;
+  border-image: linear-gradient(to right, #c0c4cc, transparent) 1;
+  white-space: nowrap;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+.section-title:first-child {
+  margin-top: 0;
+}
+.empty-data {
+  color: #909399;
+  font-size: 13px;
+  padding: 8px 0;
+}
+.plan-content {
+  padding: 8px;
+  background: #f5f7fa;
+  border-radius: 4px;
+  font-size: 13px;
+  line-height: 1.6;
+}
+</style>