Support multiple execution modes (web, CLI, API, MCP Server)

[bgervin]

PRD: Execution Modes

Objective

Support running the simulator in different environments:

• Web browser (interactive chat UI)
• CLI (self-hosted)
• API/A2A protocol
• MCP Server
• Azure-hosted (secured endpoint)

Tasks

• Design and implement web UI for interactive chat.
• Build headless API endpoints for A2A and MCP Server protocols.
• Enable CLI execution.
• Scaffold Azure hosting, including authentication for public endpoints.

Acceptance Criteria

• Simulator runs in all specified modes.
• Secured endpoints for Azure deployment.