feat: 更新文件管理组件，重命名有效期列为有效期，简化展示逻辑，提升用户体验

src/views/billManagement/fileManagement.vue

@@ -12,11 +12,7 @@
             </template>
             </template>
           </el-table-column>
           </el-table-column>
           <el-table-column prop="description" label="文件说明" min-width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
           <el-table-column prop="description" label="文件说明" min-width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
-          <el-table-column prop="validity_start" label="有效期" width="200" :show-overflow-tooltip="true" align="center">
-            <template slot-scope="scope">
-              {{ scope.row.validity_start > 0 && scope.row.validity_end > 0 ? scope.row.validity_start + ' ~ ' + scope.row.validity_end : '' }}
-            </template>
-          </el-table-column>
+          <el-table-column prop="validity_period" label="有效期" width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
           <el-table-column prop="create_name" label="上传人" width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
           <el-table-column prop="create_name" label="上传人" width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
           <el-table-column prop="create_time" label="上传时间" width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
           <el-table-column prop="create_time" label="上传时间" width="200" :show-overflow-tooltip="true" align="center"></el-table-column>
         </el-table>
         </el-table>