GitSigns is very ugly when `linehl` is enabled

[budimanjojo]

Description

It seems like there's no catppuccin color for GitSigns when configured with linehl = true. It's very ugly and I don't know if there's any suggestion for the color so I can't provide any PR.
Look at this screenshot:

The highlight name is GitSignsStagedAddLn, according to the docs: https://github.com/lewis6991/gitsigns.nvim/blob/1ee5c1fd068c81f9dd06483e639c2aa4587dc197/doc/gitsigns.txt#L1200 it fallbacks to GitSignsAddLn so I think that's where to change it. The whole GitSigns*Ln groups are not catppuccin colored from what I see in the code so maybe it's time to give it some love?

Thanks before!

Neovim version

NVIM v0.11.3
Build type: Release
LuaJIT 2.1.1741730670

Terminal and multiplexer

contour with tmux

Catppuccin version / branch / rev

v1.10.0 from nixvim 25.04

Steps to reproduce

1. Create a git repo, create a file and do git add ..
2. Open that file, do :GitSigns toggle_linehl if you don't have linehl enabled in the config.

Expected behavior

Should be beautiful

Actual behavior

Looks bad

Repro

-- DO NOT change the paths and don't remove the colorscheme
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "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", "https://github.com/folke/lazy.nvim.git", lazypath })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "catppuccin/nvim",
  -- add any other plugins here
}
require("lazy").setup(plugins, {
  root = root .. "/plugins",
})

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

[budimanjojo]

Hm, found something weird. If I call :colorscheme catppuccin-mocha then the color is then changed to catppuccin color. Maybe it's something wrong with my nixvim setup?