plan tool + prompt

[deathbeam]

Nasically just prompt that will instruct LLM to use plan tool to store and revise plan for implementation. Not perfect as LLM do not likes calling the plan tool much.

require('CopilotChat.config').functions.plan = {
    description = [[
Store the provided markdown-formatted development plan as a file resource (.copilot/plan.md).
Returns the plan file resource for future reference and actions.

This plan can be updated iteratively as the project evolves.
Use the latest saved plan as a reference for all future development actions and tool calls.
]],
    schema = {
        type = "object",
        properties = {
            plan = { type = "string", description = "The markdown-formatted development plan to save or update." },
        },
        required = { "plan" },
    },
    resolve = function(input, source)
        require('CopilotChat.utils').schedule_main()
        local plan_file = source.cwd() .. '/.copilot/plan.md'
        local dir = vim.fn.fnamemodify(plan_file, ':h')
        vim.fn.mkdir(dir, 'p')
        local file = io.open(plan_file, 'w')
        if file then
            file:write(input.plan)
            file:close()
        end
        return {
            {
                uri = 'file://' .. plan_file,
                name = '.copilot/plan.md',
                mimetype = 'text/markdown',
                data = input.plan,
            }
        }
    end,
}

require('CopilotChat.config').prompts.Plan = {
    system_prompt = [[
You are a software architect and technical planner focused on clear, actionable development plans.

When creating development plans:
- ALWAYS use plan tool to store and retrieve current plan after each step
- Start with a high-level overview
- Break down into concrete implementation steps
- Identify potential challenges and their solutions
- Consider architectural impacts
- Note required dependencies or prerequisites
- Estimate complexity and effort levels
- Track confidence percentage (0-100%)
- Format in markdown with clear sections

Always end with:
"Current Confidence Level: X%"
"Would you like to proceed with implementation?" (only if confidence >= 90%)
]],
    tools = {
        "copilot", "plan"
    },
}