When using the "Share -> Upload to NextCloud" context menu in Dolphin, the action fails because the 'Purpose' framework generates a corrupt and insecure webdav:// URL, even though the account was correctly set up in KDE Online Accounts (KAccounts) using https://.

Steps to Reproduce:

Set up a Nextcloud AIO server, which strictly enforces HTTPS.

On KDE Plasma 6, go to System Settings -> Online Accounts.

Add a Nextcloud account, ensuring the server URL is entered with the https:// prefix (e.g., https://my-server.com).

Verify that adding a 'Network Folder' in Dolphin using the webdavs:// protocol works correctly.

In Dolphin, right-click any file.

Select "Share -> Upload to NextCloud".

Expected Result: The file upload process should start, using the secure https:// (or webdavs://) protocol configured in KAccounts.

Actual Result: The action fails. The system log (via journalctl) shows that Plasma is trying to use a syntactically incorrect, insecure URL:
```
Okt 30 17:29:16 viper3 plasmashell[906]: org.kde.plasma.notifications: Failed to determine mime type for QUrl("webdav://admin@censoredurl.ddns.net//remote.php/dav/files/admin/") "Die Datei oder der Ordner webdav://admin@censoredurl.ddns.net//remote.php/dav/files/admin/ existiert nicht."
```

It is using webdav:// (HTTP) instead of the configured https:// (or webdavs://). My server correctly blocks this insecure request, so it never even receives it.

Environment:
KDE Plasma Version: 6.3.6
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2
Kernel Version: 6.12.48-1-MANJARO 64bit

Server: Nextcloud AIO (Docker) enforcing HTTPS.