The previous/next actions don't work correctly when the current buffer is a spread

[tllilleh]

Here is a minimal bujo-init.lua to reproduce the issue:

vim.g.mapleader = " "

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 = {
        {
            "timhugh/bujo.nvim",
            dependencies = {
                "nvim-telescope/telescope.nvim",
                "leafo/etlua",
                "michaelb/sniprun",
            },
            opts = {
                spreads = {
                    weekly = {
                        filename_template = "%Y/W%V",
                        now_keybind = "<leader>nw",
                        next_keybind = "<leader>nf",
                        previous_keybind = "<leader>nb",
                    },
                },
            },
        },
    },
})

To test I run: nvim -u bujo-init.lua

From a normal buffer all three of these actions work as expected.

However, if I run <leader>nw to open the current week's spread (currently ~/.bujo/2025/W34.md) and then run <leader>nb while the spread is open it opens ~/.bujo/2024/W01.md instead of the expected ~/.bujo/2025/W33.md). If I run <leader>nf from the current week's spread it opens ~/.bujo/2025/W02.md instead of the expected ~/.bujo/2025/W35.md.

System Info:

$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 22.04.5 LTS
Release:	22.04
Codename:	jammy

$ nvim --version
NVIM v0.11.3
Build type: Release
LuaJIT 2.1.1741730670
Run "nvim -V1 -v" for more info