New threat by type/context throws error on edges

[lreading]

Describe the bug: New threat by type and new threat by context throw an error when using them on an edge. The new threat button is disabled, so I suspect this is an unintended workflow.

Expected behaviour: Should we disable these buttons when the "New Threat" button is disabled? I'm not sure how this is used.

Environment:

• Version: 2.2.0-latest
• Platform: Web App
• OS: Ubuntu 24.04
• Browser: Vivaldi (chromium based)

To Reproduce:

1. Create a new Diagram
2. Add a trust boundary curve
3. Select the edge (tb curve)
4. Click either "New Threat By Type" or "New Threat By Context"
5. Attempt to save
6. Threat is not saved, and there are errors in the console

Any additional context, screenshots, etc: