[BWA-188] Authenticator Export JSON is Empty

### Steps To Reproduce

Authenticator TOTP Codes are synced with Bitwarden App
Authenticator ... Settings ... Export

### Expected Result

Expecting all sites with TOTP codes to be present in the JSON file

### Actual Result

```
encrypted false
items []
```

Expand all ... reveals nothing and the resulting JSON is only 30 byte.

### Screenshots or Videos

_No response_

### Additional Context

_No response_

### Build Version

2025.7.1 (102)

### What server are you connecting to?

Self-host

### Self-host Server Version

2025.7.0

### Environment Details

iPhone 14 Pro iOS 18.6.1

### Issue Tracking Info

- [x] I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

The issue names no source file or test. Start by reproducing the empty export on an iPhone using the listed app and server versions, then trace the Authenticator export flow and synced TOTP data. Done means the exported JSON contains all sites with TOTP codes rather than an empty items array.

Written by the indexing model from the issue text.