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/assertString.js

@@ -0,0 +1,12 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = assertString;
+function assertString(input) {
+  if (input === undefined || input === null) throw new TypeError("Expected a string but received a ".concat(input));
+  if (input.constructor.name !== 'String') throw new TypeError("Expected a string but received a ".concat(input.constructor.name));
+}
+module.exports = exports.default;
+module.exports.default = exports.default;