Define UI pattern for adding extra context types to the FlowFuse expert, like the 📎

### Description

Example, not exact solution: <img width="757" height="497" alt="Image" src="https://github.com/user-attachments/assets/394a70db-6e45-40a7-ac63-f3f6b4ccd667" />

### Epic/Story

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate