Lock Vault ios shortcuts error

### Summary

The action Lock Vault throws an error

### Please agree to the following

- [x] I have searched [existing issues](https://github.com/cryptomator/cryptomator/issues?q=) for duplicates
- [x] I agree to follow this project's [Code of Conduct](https://github.com/cryptomator/cryptomator/blob/develop/.github/CODE_OF_CONDUCT.md)

### What software is involved?

- Operating System: iOS 26.2
- Cryptomator: 2.7.3
- local vault

### Volume Type

None

### Steps to Reproduce

1. Add a lock vault action in ios shortcuts
2. Execute the action it may work for 1 or two times but fails thereafter.

### Expected Behavior

Should lock the vault

### Actual Behavior

Different lock the vault

### Reproducibility

Always

### Relevant Log Output

```shell

```

### Anything else?

_No response_

Start by reproducing the Lock Vault action in iOS Shortcuts with a local vault, as described in the issue, and capture the error since no relevant log output is provided. Done means the action reliably locks the vault after repeated executions.

Written by the indexing model from the issue text.