Add agent selection to Eliza interface menu

[mihai169]

Selection of agents should be available not only at the beginning but also as an option in the left menu to be able to change the menu.

Acceptance Criteria:
The system should allow users to select an agent at the beginning of the process (if not already selected).
After the initial selection, the user should be able to change the agent selection from the left menu at any time.
The left menu should display a "Change Agent" option that opens a list of available agents.
The user should be able to select a different agent from the list in the left menu.
Once a new agent is selected from the left menu, the system should update the agent context immediately and reflect it in the UI.

Test Cases
Feature: Agent Selection and Change via Left Menu

As a user,
I want to be able to select an agent at the beginning and change the agent later via the left menu,
So that I can update the agent context anytime without needing to reload the page.

Scenario: Select an agent at the beginning
Given the user is on the home screen
When the user sees the "Select Agent" screen
And the user selects an agent from the available list
Then the selected agent should be displayed in the UI
And the agent context should be set to the selected agent

Scenario: Change the selected agent via the left menu
Given the user has selected an agent initially
When the user clicks on the "Change Agent" option in the left menu
And the user selects a different agent from the list
Then the selected agent in the UI should update to the newly selected agent
And the agent context should be updated to the newly selected agent
And no page reload should be required

Scenario: Left menu displays "Change Agent" option
Given the user is logged into the system
When the user views the left menu
Then the "Change Agent" option should be visible in the menu
And the "Change Agent" option should open a list of available agents when clicked

[github-actions]

Hello @mihai169! Welcome to the ai16z community. Thank you for opening your first issue; we appreciate your contribution. You are now a ai16z contributor!

[snobbee]

@mihai169 the new Eliza UI allows to move from one agent to another from the left side panel anytime in the UI see the screengrab for a demo here #212 (comment)