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/buffer-equal-constant-time/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "buffer-equal-constant-time",
+  "version": "1.0.1",
+  "description": "Constant-time comparison of Buffers",
+  "main": "index.js",
+  "scripts": {
+    "test": "mocha test.js"
+  },
+  "repository": "git@github.com:goinstant/buffer-equal-constant-time.git",
+  "keywords": [
+    "buffer",
+    "equal",
+    "constant-time",
+    "crypto"
+  ],
+  "author": "GoInstant Inc., a salesforce.com company",
+  "license": "BSD-3-Clause",
+  "devDependencies": {
+    "mocha": "~1.15.1"
+  }
+}