Desktop Brand Builder (Tauri shell)

Goal

Create a branded desktop package from packages/desktop-shell with the least user input possible. The user should usually provide only:

brandId: acme-ai
logo: /absolute/path/to/logo.png
website: https://acme.ai

website is optional. Do not ask for app name, app id, artifact name, copyright, or updater endpoints unless the user explicitly asks to override them.