bug: `layout.set_winlayout` inserts windows in wrong order

[zemzelett]

Did you check the docs and existing issues?

• [X] I have read the docs
• [X] I have searched the existing issues

Neovim version (nvim -v)

0.9.2

Operating system/version

MacOS 13.5.1

Describe the bug

Windows are inserted in reverse order to what they were saved in.

This is due to the fact that a (v)split, by default, either splits to the left or top. Resession saves windows in order from left to right as vim.fn.winlayout returns them. When inserting these, the windows have to be splitted to the right or below in order to reflect the saved order.

Steps To Reproduce

1. Open a tab with at least 2 windows split vertically, horizontally or mixed (The loaded files should be visually easily distinguishable.
2. Save the session
3. Load the session (The windows are in the wrong order)

Expected Behavior

Splits are restored in the same order as they were saved in.

Directory structure

Any set of files is sufficient as long as they have different content, so the order is obviously visible.

Repro

-- save as repro.lua
-- run with nvim -u repro.lua
-- DO NOT change the paths
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "runtime", "cache" }) do
  vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end

-- bootstrap lazy
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
  vim.fn.system({
    "git",
    "clone",
    "--filter=blob:none",
    "--single-branch",
    "https://github.com/folke/lazy.nvim.git",
    lazypath,
  })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "folke/tokyonight.nvim",
  {
        "stevearc/resession.nvim",
        config = function()
            require("resession").setup()
        end,
  },
  -- add any other plugins here
}
require("lazy").setup(plugins, {
  root = root .. "/plugins",
})

vim.cmd.colorscheme("tokyonight")
-- add anything else here

vim.g.mapleader = " "
local resession = require('resession')
vim.keymap.set('n', '<leader>ss', resession.save)
vim.keymap.set('n', '<leader>sl', resession.load)

Did you check the bug with a clean config?

• [X] I have confirmed that the bug reproduces with nvim -u repro.lua using the repro.lua file above.