Files provided via a public link with write access will not be downloaded by the NextCloud Desktop Client (MacOS)

### ⚠️ 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

I encountered following bug using the most recent version of NextCloud Server along with the 3 most recent Desktop Clients (34.0.1 up to 34.0.3 as of today and maybe all earlier versions) on macOS Tahoe 26.6.2 on MacBook Air M4.

When a file gets uploaded via a shared link which is "public" - it will be uploaded to the server, but never occurs on the desktop client. See "Steps to reproduce".

### Steps to reproduce

* Use the Desktop Client with VFS on
* Create a directory using the Desktop Client and share it as "external link" so any external user with that link can upload a file
* Upload some file via that link in the browser (no matter which size or type)
* Desktop Client shows under "Activity" that a file has been uploaded. Correct!
* Looking into the shared folder via browser on the NextCloud Server shows that the file is really there. Correct!
* BUT: the Desktop Client will never download it. Even when restarting it or waiting for hours.
* Workaround: Force download of that folder in Desktop Client via "Keep offline" in the context menu of the respective shared directory - then (and only then!) immediately the file(s) will appear in Finder.

### Expected behavior

When some file has been uploaded to a publicly shared folder, the respective file should appear on the desktop client's side in Finder without any further interaction.

### Which files are affected by this bug

All files which are uploaded via a public shared link

### Operating system

macOS

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

MacOS 26.6.2

### Installation method

Official Installer for macOS 13 and later

### Nextcloud Server version

33.0.6.2

### 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?

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

### Nextcloud Server logs

```shell

```

### Additional info

_No response_

No source files or tests are identified in the report. Start by reproducing the issue with VFS enabled: create a publicly writable shared folder, upload a file through the browser link, and compare Activity, the server folder, and Finder. Done means the uploaded file appears in Finder without using Keep offline or restarting the client.

Written by the indexing model from the issue text.