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/@smithy/util-stream/dist-es/splitStream.js

@@ -0,0 +1,13 @@
+import { PassThrough } from "stream";
+import { splitStream as splitWebStream } from "./splitStream.browser";
+import { isBlob, isReadableStream } from "./stream-type-check";
+export async function splitStream(stream) {
+    if (isReadableStream(stream) || isBlob(stream)) {
+        return splitWebStream(stream);
+    }
+    const stream1 = new PassThrough();
+    const stream2 = new PassThrough();
+    stream.pipe(stream1);
+    stream.pipe(stream2);
+    return [stream1, stream2];
+}