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/es/lib/ltrim.js

@@ -0,0 +1,7 @@
+import assertString from './util/assertString';
+export default function ltrim(str, chars) {
+  assertString(str);
+  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#Escaping
+  var pattern = chars ? new RegExp("^[".concat(chars.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), "]+"), 'g') : /^\s+/g;
+  return str.replace(pattern, '');
+}