[PM-40489] Export vault to another app fails immediately after tapping Export items

### Steps To Reproduce

1. Open the Bitwarden iOS app.
2. Navigate to **Settings** → **Vault** → **Export vault**.
3. Select **Export vault to another app**.
4. The export summary screen appears, showing the vault contents grouped by item type (Passwords, Passkeys, Cards, Identities, and Secure notes) along with the item count for each type.
5. Tap **Export items**.

### Expected Result

After tapping **Export items**, the user should be prompted to choose a destination application to receive the exported vault data (for example, Apple Passwords or another compatible credential manager).

### Actual Result

Immediately after tapping **Export items**, a failure screen is displayed with the message::

> "Export failed: There has been an issue exporting items."

The destination application selection interface never appears.

### Screenshots or Videos

Screenshot showing the error displayed immediately after tapping **Export items**...

### Additional Context

- The export summary screen loads successfully and correctly displays all vault item categories and their respective counts before the failure occurs.
- The failure occurs immediately after tapping **Export items**.
- The issue has been reproduced consistently.

### Build Version

2026.6.1 (3376)

### What server are you connecting to?

US

### Self-host Server Version

_No response_

### Environment Details

- Device: iPhone 16 Pro
- iOS Version: 26.5.2

### 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.

Start by reproducing the Export vault to another app flow on the reported iOS build and trace what happens after Export items is tapped. Focus on the export path before the destination-app picker; done means the picker appears and the exported vault data can be handed to a compatible app without the failure screen.

Written by the indexing model from the issue text.