BUG: Sidekick crashes when clicking the links while downloading the default model.

[kspeeckaert]

Describe the bug
Sidekick crashes when clicking the links while downloading the default model.

To Reproduce
Steps to reproduce the behavior:

1. Open the app for the first time and get the model download dialog
2. Click on 'Download default model'
3. As it's downloading, click on the 'Use GGUF model', then click cancel in the file dialog
4. Sidekick crashes.

Expected behavior
Sidekick should either continue downloading or have disabled the links as it started downloading.

Desktop:

• OS: macOS 26.4
• Version Sidekick 1.0.0-rc.18

[kspeeckaert]

Apparently the download continues in the background, as it was nearly finished when I reopened Sidekick, which is rather strange.