AI Agent Modules: Add support for `agentapi` Web UI

[bpmct]

The AgentAPI web UI is a great UI-based alternative to the TUI-style of Coding agents. We have a template here.

Let's add stuff like

• install_agentapi = <true/false> (default false) install agentapi from github
• agentapi_version = "<0.2.1>"
• agentapi_app = <true/false> (default false) to expose the agentapi web ui as a coder_app.
• tui_app = <true/false> (default true) to whether we want to show the TUI

[matifali]

tui_app = <true/false> (default true) to whether we want to show the TUI

This only controls the TUI coder_app. Right?

[bpmct]

Correct. And whether it should be rendered.