fix: Resolve Hyva theme installation in interactive installer

[marcelmtz]

Description (*)

This PR fixes Hyva theme installation in the interactive installer introduced by PR mage-os#191.

Three bugs were identified during manual testing that prevented the Hyva theme from being
applied after installation:

1. ThemeConfiguration VO dropped Hyva credentials — hyva_project_key and
   hyva_api_token were collected during the theme config stage but never stored in the
   Value Object, causing ThemeInstaller to always receive empty credentials and abort
   with "Hyva credentials are required".

2. theme:list is not a valid Magento CLI command — ThemeConfigurer::getThemeId()
   called bin/magento theme:list which does not exist, causing theme application to
   silently fail for all non-Luma themes. Replaced with a direct PDO query against the
   theme table, following the same pattern already used in DatabaseValidator.

3. Hyva API token excluded from toArray() output — ThemeInstallationStage called
   $theme->toArray() without the $includeSensitive flag, so the API token was never
   passed to HyvaInstaller.

Related Pull Requests

• Feature/interactive installer mage-os/mageos-magento2#191 (mage-os/mageos-magento2) — Interactive Installer (this PR fixes bugs in that branch)

Fixed Issues (if relevant)

No dedicated issue — bugs were found during manual testing of PR mage-os#191.

Manual testing scenarios (*)

1. Start with a clean environment (no env.php, empty database)
2. Run bin/magento install
3. Progress through all stages, selecting Hyva as the theme when prompted
4. Enter valid Hyva project key and API token from your Hyva account dashboard
   (Repo URL format: https://hyva-themes.repo.packagist.com/{project-key}/)
5. Complete the installation
6. Verify the storefront loads with the Hyva theme applied
7. Confirm no "Could not find theme" or "Hyva credentials are required" warnings appear
   in the post-install output

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• README.md files for modified modules are updated and included in the pull request if any predefined sections require an update
• All automated tests passed successfully (all builds are green)

Note: I left the two checklist items unchecked — unit tests for the PDO-based getThemeId() weren't added in this session, and CI hasn't run yet on your fork.