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/_getValue.js

@@ -0,0 +1,13 @@
+/**
+ * Gets the value at `key` of `object`.
+ *
+ * @private
+ * @param {Object} [object] The object to query.
+ * @param {string} key The key of the property to get.
+ * @returns {*} Returns the property value.
+ */
+function getValue(object, key) {
+  return object == null ? undefined : object[key];
+}
+
+module.exports = getValue;