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/lodash/identity.js

@@ -0,0 +1,21 @@
+/**
+ * This method returns the first argument it receives.
+ *
+ * @static
+ * @since 0.1.0
+ * @memberOf _
+ * @category Util
+ * @param {*} value Any value.
+ * @returns {*} Returns `value`.
+ * @example
+ *
+ * var object = { 'a': 1 };
+ *
+ * console.log(_.identity(object) === object);
+ * // => true
+ */
+function identity(value) {
+  return value;
+}
+
+module.exports = identity;