[FEATURE] Desktop app: highlight the currently open project/environment in the sidebar

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

After the desktop app redesign, it is hard to tell which project (environment) is currently open in the sidebar. When there are many projects and sessions, nothing visually distinguishes the active one from the rest, so I lose track of where I am and have to read every entry to find it.

Proposed Solution

Clearly highlight the active project/environment in the sidebar (e.g. a background color, bold text, or an indicator), the same way the selected session is highlighted. This should also work when grouping by project.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

_No response_

Additional Context

I work on several related projects at the same time (around 10 projects, each with many sessions). When I switch between sessions, I need to know which project/environment I'm currently in. Right now the sidebar looks the same for every project, so I have to read each name and match it against the session title to confirm where I am. With a clearly highlighted active project, I'd see it at a glance, and I wouldn't risk starting a task in the wrong project.