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/head.js

@@ -0,0 +1,23 @@
+/**
+ * Gets the first element of `array`.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @alias first
+ * @category Array
+ * @param {Array} array The array to query.
+ * @returns {*} Returns the first element of `array`.
+ * @example
+ *
+ * _.head([1, 2, 3]);
+ * // => 1
+ *
+ * _.head([]);
+ * // => undefined
+ */
+function head(array) {
+  return (array && array.length) ? array[0] : undefined;
+}
+
+module.exports = head;