bug: after opencode's update to 1.14.30, `sidekick.send` stopped working

[ruicsh]

Did you check docs and existing issues?

• I have read all the sidekick.nvim docs
• I have updated the plugin to the latest version before submitting this issue
• I have searched the existing issues of sidekick.nvim
• I have searched the existing issues of plugins related to this issue

Neovim version (nvim -v)

NVIM v0.12.2

Operating system/version

MacOS 26.4.1

Describe the bug

After updating OpenCode to 1.14.30, it stopped being possible to use sidekick.send to inject prompts, files, or any context variables into opencode. It launches OpenCode, but the prompt is empty.

Steps To Reproduce

1. call cli.prompt
2. pick any prompt
3. Select CLI tool: opencode

assert that OpenCode is opened, but there's no prompt inserted on the input field.

Expected Behavior

Before 1.14.30, we could inject prompts and context variables into opencode from sidekick

Repro

vim.env.LAZY_STDPATH = ".repro"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro({
  spec = {
    { "folke/sidekick.nvim", opts = {} },
    -- add any other plugins here
  },
})

[PengfeiM]

my opencode 1.15.5 works fine.
may be you can upgrade opencode to see if it happens again

[ruicsh]

not yet, even with OpenCode 1.15.5. I'll update the reproduction steps:

vim.env.LAZY_STDPATH = ".repro"
load(vim.fn.system("curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"))()

require("lazy.minit").repro({
  spec = {
    { 
      "folke/sidekick.nvim", 
      keys = function()
        local cli = require("sidekick.cli")

        function send_hello()
          cli.send({ name = "opencode", msg = "Hello" })
        end

        return {
          { "<c-y>", send_hello, mode = { "n", "t", "i" }, desc = "Sidekick: Hello" }
        }
      end,
      opts = {} 
    },
  },
})

pressing <c-y>, opens sidekick, but OpenCode's prompt is not filled in with "Hello". Before 1.14.30, this did work.