bug: size (width) is not applied with zellij

[n-prat]

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 v0.11.5 Build type: RelWithDebInfo LuaJIT 2.1.1764270282 Run "nvim -V1 -v" for more info

Operating system/version

Linux archvm 6.17.9-arch1-1 #1 SMP PREEMPT_DYNAMIC Mon, 24 Nov 2025 15:21:09 +0000 x86_64 GNU/Linux

Describe the bug

I tried various ways to set mux.split.size with zellij backend but could not get it to work.

For now, after a bit of Claude, I went with this, which seems to work:

{
    'folke/sidekick.nvim',
    opts = {
      cli = {
        mux = {
          backend = 'zellij',
          enabled = true,
          split = {
            vertical = true,
            -- size = 0.3, -- default: 0.5 -- NOT WORKING with zellij
            -- size = 60, -- NOT WORKING either
          },
        },
        win = {
          layout = 'right',
          split = {
            width = 0, -- Set to 0 so the default logic ignores it initially
          },
          -- The Magic Hook
          config = function(terminal)
            -- terminal.opts is a deepcopy of Config.cli.win
            -- We can calculate the integer width here dynamically
            terminal.opts.split.width = math.floor(vim.o.columns * 0.40)
          end,
        },
      },
      -- NES = Next Edit Suggestions: requires Copilot
      nes = { enabled = false },
    },
  },

Steps To Reproduce

1. (not sure if it has an impact) run Neovim inside Zellij session
2. update/set mux.split.size
3. quit or ctrl-c any active cli [double check with zellij list-sessions to make sure they are killed]
4. restart nvim
5. toggle a new cli

NOTE : my stack is Windowa host, running wezterm, which itself use SSHMUX to connect to a Linux guest VM, which is running zellij as a multiplexer. Inside which I start nvim

Expected Behavior

The size should be set based on the config value.

Repro

[BitCalSaul]

@n-prat hi i encounter same issue, i use tmux but not enabled.