Allow launching copilot in plan/autopilot mode with --plan or --autopilot flags

[logar16]

Describe the feature or problem you'd like to solve

I would like a way to launch copilot already in the desired mode. I have scripts that launch new instances of copilot and it would be helpful if they could launch them in plan mode instead of requiring me to manually make that switch. Might as well support autopilot mode too.

Proposed solution

For anyone who is benefitting from launching copilot via a script (e.g., from another copilot session where user asks copilot to make a new terminal running copilot), it's helpful to have as much control over the session as possible via command line args. I suggest that you could either easily add yet another input parameter such as --plan or --autopilot or even --review and other modes/agents OR you could have some pass-through command that lets user pass in json or something that describes all the settings desired instead of requiring a bunch of flags. This would allow copilot to launch itself in a variety of useful ways.
I personally have a skill that tells Copilot how to launch a new tab of Windows Terminal, color the tab and label and pass in a [PLAN] prompt. But after the first response, I have to manually go put it into plan mode or else it doesn't get the plan mode prompt.
I'm also finding it hard to do things like have the session named automatically. Having a way to specify that either through a --name parameter or, again, an input to specify all the desired settings as a json object/file, would make life way easier to automate.

Example prompts or workflows

1. Launch new Copilot session already in plan mode with starting prompt
2. Have Copilot session launch another session tackling an adjacent task, new session starts up in autopilot mode and makes the changes right away (or could have been in plan mode or just normal interactive mode)
3. Have a way to launch Copilot sessions with super specific settings that are currently not available to be passed in as parameters and will require an issue for each one...

Additional context

No response