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/nodemailer/.gitattributes

@@ -0,0 +1,6 @@
+*.js text eol=lf
+*.txt text eol=lf
+*.html text eol=lf
+*.htm text eol=lf
+*.ics -text
+*.bin -text