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/bl/test/convert.js

@@ -0,0 +1,21 @@
+'use strict'
+
+const tape = require('tape')
+const { BufferList, BufferListStream } = require('../')
+const { Buffer } = require('buffer')
+
+tape('convert from BufferList to BufferListStream', (t) => {
+  const data = Buffer.from(`TEST-${Date.now()}`)
+  const bl = new BufferList(data)
+  const bls = new BufferListStream(bl)
+  t.ok(bl.slice().equals(bls.slice()))
+  t.end()
+})
+
+tape('convert from BufferListStream to BufferList', (t) => {
+  const data = Buffer.from(`TEST-${Date.now()}`)
+  const bls = new BufferListStream(data)
+  const bl = new BufferList(bls)
+  t.ok(bl.slice().equals(bls.slice()))
+  t.end()
+})