fix: 修复配额说明重复和undefined问题

- 在editStorageForm中初始化oss_storage_quota_value和oss_quota_unit
- 删除重复的旧配额说明块，保留新的当前配额设置显示

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

backend/node_modules/validator/lib/util/nullUndefinedCheck.js

@@ -0,0 +1,11 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = isNullOrUndefined;
+function isNullOrUndefined(value) {
+  return value === null || value === undefined;
+}
+module.exports = exports.default;
+module.exports.default = exports.default;