Feat: add hyva theme install for local dev environment

[dermatz]

This pull request updates the Magento installation script to integrate the Hyvä theme and its dependencies into the project setup. The main changes involve configuring multiple Hyvä-related GitHub repositories as Composer sources and ensuring the Hyvä default theme is required alongside the main module during installation.

Hyvä theme integration:

• Added Composer configuration for several Hyvä theme-related GitHub repositories to ensure all required packages can be installed directly from their sources.
• Updated the Composer require command to include the hyva-themes/magento2-default-theme package, ensuring the Hyvä theme is installed together with the main openforgeproject/mageforge module.

[Copilot]

Pull request overview

Adds an optional, interactive Hyvä theme installation step to the local ddev install-magento workflow, integrating Hyvä setup into the Magento bootstrap process for developers who have a Hyvä license.

Changes:

• Prompt the user during install to optionally install Hyvä and capture repo URL + token.
• Configure Composer to access the Hyvä repository and require the Hyvä default theme package.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.