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/@aws-sdk/middleware-user-agent/dist-es/encode-features.js

@@ -0,0 +1,18 @@
+const BYTE_LIMIT = 1024;
+export function encodeFeatures(features) {
+    let buffer = "";
+    for (const key in features) {
+        const val = features[key];
+        if (buffer.length + val.length + 1 <= BYTE_LIMIT) {
+            if (buffer.length) {
+                buffer += "," + val;
+            }
+            else {
+                buffer += val;
+            }
+            continue;
+        }
+        break;
+    }
+    return buffer;
+}