MorrowOS v1.3

Automated build. BIOS + UEFI, 64-bit.

Boot splash: stock (the branding step fell back — see the run log).
Boot menu: MorrowOS Dawn theme.
Installer: installs to disk as MorrowOS.

SHA256 of the assembled ISO:

fcd8265d02ae96e3ca77f3472463f89eddcc222be31e878fbfa58217d1b58f7c  morrowos-v1.3.iso

The ISO exceeds GitHub's 2 GiB per-asset limit, so it is
published as numbered parts. Download every .part* file
into one folder, then reassemble:

Linux / macOS

cat morrowos-v1.3.iso.part* > morrowos-v1.3.iso
sha256sum -c morrowos-v1.3.iso.sha256

Windows — simplest (Command Prompt, in the folder with the parts)

copy /b morrowos-v1.3.iso.part00 + morrowos-v1.3.iso.part01 + morrowos-v1.3.iso.part02 morrowos-v1.3.iso

Then check it in PowerShell:

(Get-FileHash "morrowos-v1.3.iso" -Algorithm SHA256).Hash.ToLower()

Windows — PowerShell alternative

Three things here are deliberate and were each a real bug:
Join-Path $PWD.Path because .NET APIs resolve relative paths
against the process working directory, NOT PowerShell's location;
File::Create rather than OpenWrite because OpenWrite does not
truncate, so re-running over an existing file leaves trailing bytes
and a wrong hash; and CopyTo rather than ReadAllBytes because
a 1900 MiB part read whole sits right at the ~2 GB .NET array limit.

$dir = $PWD.Path
$iso = Join-Path $dir "morrowos-v1.3.iso"
$out = [System.IO.File]::Create($iso)
Get-ChildItem (Join-Path $dir "morrowos-v1.3.iso.part*") | Sort-Object Name | ForEach-Object {
    $in = [System.IO.File]::OpenRead($_.FullName)
    $in.CopyTo($out)
    $in.Close()
}
$out.Close()
(Get-FileHash $iso -Algorithm SHA256).Hash.ToLower()

Compare that hash against the one above before booting it.

See the README for the full change list and known gaps.