`sticky` prompts provided to `open()` do not appear in chat window

[garcia5]

Description

When I open the chat window with a sticky prompt specified in the config I pass in, those sticky messages are not shown in the chat window. This appears to be related to 1ff0bb3

Reproducer

:lua require("CopilotChat").open({ sticky = { "@copilot", "A custom sticky message" } })

Current Behavior

Expected Behavior

---

Config

local chat = {
    "CopilotC-Nvim/CopilotChat.nvim",
    branch = "main",
    dependencies = {
        { "zbirenbaum/copilot.lua" },
        { "nvim-lua/plenary.nvim" },
    },
    build = "make tiktoken",
    opts = {
        debug = false,
        model = "claude-sonnet-4", -- default model
        auto_insert_mode = false, -- Automatically enter insert mode when opening window and on new prompt
        insert_at_end = false, -- Move cursor to end of buffer when inserting text
        remember_as_sticky = true,
        diff = "block", -- default to markdown diff blocks
        sticky = { "@copilot" }, -- automatically use copilot tools in every sesssion
        -- open window in right 1/3rd of window
        window = {
            layout = "vertical",
            width = 0.3,
            title = " Copilot Chat",
        },
        headers = {
            user = "󰀉 User",
            assistant = "󰚩 Assistant",
            tool = "󱁤 Tool",
        },
        -- Use render-markdown for nicer rendering
        highlight_headers = true,
        separator = "---",
        error_header = "> [!ERROR] Error",
        -- custom prompts
        prompts = {
            PythonExpert = {
                system_prompt = "You are an expert Python developer with knowledge of language best practices, helping an experienced software engineer in their day to day work",
            },
        },
        -- custom mappings within copilot chat buffer
        mappings = {
            submit_prompt = {
                normal = "<CR>",
                insert = "<C-y>",
            },
            accept_diff = {
                normal = "<C-s>",
                insert = "<C-s>",
            },
            -- make it hard to accidentally reset the chat
            reset = {
                normal = "ggr",
                insert = "<C-r><C-y>",
            },
        },
    },
    keys = {
        {
            "<Leader>co",
            function()
                local config = {}
                if vim.bo.filetype == "python" then config.sticky = {"@copilot", "/PythonExpert"} end
                require("CopilotChat").open(config) end,
            mode = { "n", "v" },
        },
    },
    cmd = {
        "CopilotChat",
        "CopilotChatOpen",
        "CopilotChatToggle",
        "CopilotChatExplain",
        "CopilotChatReview",
        "CopilotChatFix",
        "CopilotChatOptimize",
        "CopilotChatDocs",
        "CopilotChatTests",
        "CopilotChatFixDiagnostic",
        "CopilotChatCommit",
        "CopilotChatCommitStaged",
        "CopilotChatModels",
        "CopilotChatLoad",
    },
    init = function()
        vim.api.nvim_create_autocmd("BufEnter", {
            pattern = "copilot-*",
            callback = function()
                vim.opt_local.relativenumber = false
                vim.opt_local.number = false
            end,
        })
    end,
}