Copilot CLI can run in headless mode and can communicate through RPC-JSON

... and so does Vim through `ch_open()`. :)

What about improving this plugin by exploiting Vim job & channels to communicate to copilot CLI?

I would see an interface made by a window split where one window contains a prompt buffer (with history and omnicomplete function triggered when hitting `/` key), and another window to display the response from the server.

For copilot CLI commands that require selection, like for example model selection and resume sessions, one could use popups and the statusline can be embellished by including the AIC for the current session.

... these are ideas just from top of my head.

Start by reviewing the plugin's existing command and session entry points, then investigate Vim job and channel support alongside the Copilot CLI's headless RPC-JSON interface. Before implementation, clarify which parts of the proposed prompt, response, popup, and statusline experience are required; done should include a working end-to-end communication flow and the agreed UI behavior.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.