"Waiting" state does not explain current agent activity

## Reported behavior

A user reported that sessions can show "Waiting" for several minutes without any indication of what the agent is doing.

This makes it difficult to tell whether the agent is thinking, compacting context, waiting on a service, or stuck.

## Expected behavior

When a session shows "Waiting," users should be able to see the current activity or status. The app does not need to expose chain of thought, but it should provide enough information to show that work is continuing and where time is being spent.

No file or test is named. Start by locating the desktop UI that renders the "Waiting" state and trace how agent activity is represented; done means users can distinguish ongoing work such as thinking, context compaction, service waits, or a stuck session without exposing chain of thought.

Written by the indexing model from the issue text.