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-base64/dist-es/toBase64.js

@@ -0,0 +1,15 @@
+import { fromArrayBuffer } from "@smithy/util-buffer-from";
+import { fromUtf8 } from "@smithy/util-utf8";
+export const toBase64 = (_input) => {
+    let input;
+    if (typeof _input === "string") {
+        input = fromUtf8(_input);
+    }
+    else {
+        input = _input;
+    }
+    if (typeof input !== "object" || typeof input.byteOffset !== "number" || typeof input.byteLength !== "number") {
+        throw new Error("@smithy/util-base64: toBase64 encoder function only accepts string | Uint8Array.");
+    }
+    return fromArrayBuffer(input.buffer, input.byteOffset, input.byteLength).toString("base64");
+};