Windows - Can't add second nextcloud instance

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I have searched for it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

The UI changed on the Windows Client, and there is no button to add another account.
This is the complete settings-screen:

There is also no option at the three dot menu there:

Not on right mouse click:

And not in the main window:

Why is the button missing?

### Steps to reproduce

See above, there are unfortunately no steps, as the button to add a new nextcloud instance is missing

### Expected behavior

There should be a button to add another nextcloud instance

### Which files are affected by this bug

all files?

### Operating system

Windows

### Which version of the operating system you are running.

Windows 11

### Installation method

Official Windows MSI

### Nextcloud Server version

33.0.5

### Nextcloud Desktop Client version

34.0.3

### Did this occur after an update or on a clean installation?

Minor version update (i.e. 33.0.0 → 33.0.1)

### Are you using the Nextcloud Server Encryption module?

No

### Are you using an external user-backend?

- [x] Default internal user-backend
- [ ] LDAP or Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

```shell
n/a
```

### Additional info

_No response_

Start by reproducing the missing add-account control on Windows 11 with the reported Desktop Client version, checking the settings screen, three-dot menu, context menu, and main window described in the report. Trace the desktop UI entry point responsible for account management and verify that the completed change provides a visible way to add a second instance without removing existing accounts.

Written by the indexing model from the issue text.