Sidepanel organisation of sessions into features/projects

### Feature summary

_No response_

### What problem are you trying to solve?

Often times, my feature goes across multiple repos and it quickly becomes very confusing which sessions work on which feature as they are organized in repositories.

### Proposed solution

I would very much like to be able to seperate my agent sessions into projects/features in the leftside bar. Visually clearly seperated, perhaps not only in dropdowns, but also with bounding boxes around a project/feature. Being able to organise into features rather than repositories would be very valuable.

### Workflow impact

People with features spanding across multiple repos would get an option to have a better overview.

### Installation context

_No response_

### Additional context

_No response_