/agent - Leave scroll position at top of picklist

### Describe the feature or problem you'd like to solve

As a user, when searching for an agent, I don't want to take my hands off the keyboard to mouse scroll up to the top of the agent selection list

### Proposed solution

Leave the scroll position such that the top of the agent list is displayed, where I can then start a search and see the fiiltered results

### Example prompts or workflows

_No response_

### Additional context

Start at the /agent picklist entry point and inspect how the agent selection list's scroll position is initialized. Done means opening the list displays its top so a user can begin searching from the keyboard without manually scrolling.

Scritto dal modello di indicizzazione a partire dal testo della issue.