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/signal-exit/dist/mjs/browser.d.ts

@@ -0,0 +1,12 @@
+/**
+ * This is a browser shim that provides the same functional interface
+ * as the main node export, but it does nothing.
+ * @module
+ */
+import type { Handler } from './index.js';
+export declare const onExit: (cb: Handler, opts: {
+    alwaysLast?: boolean;
+}) => () => void;
+export declare const load: () => void;
+export declare const unload: () => void;
+//# sourceMappingURL=browser.d.ts.map