fix frontend inspector to be compatible with magento standard themes like luma and base

[dermatz]

This pull request focuses on improving the MageForge Inspector's compatibility and maintainability by migrating its CSS from Tailwind to pure Vanilla CSS, ensuring it works seamlessly across all Magento 2 frontend themes (including both Luma and Hyvä). It also introduces automated functional tests to validate the Inspector's assets, CSS conventions, and Alpine.js loading behavior.

Key changes:

Inspector CSS Migration and Compatibility:

• Migrated Inspector component CSS from Tailwind to pure Vanilla CSS, using the mageforge-* prefix for all classes, removed the Tailwind build dependency, and updated the CSS location to src/view/frontend/web/css/inspector.css for better compatibility and namespace isolation.
• Updated the Inspector template (inspector.phtml) to automatically load Alpine.js from a CDN only if it is not already present (ensuring compatibility with both Luma and Hyvä themes), with appropriate detection and logging.

Automated Functional Testing:

• Added a comprehensive Inspector functionality test step to the GitHub Actions workflow. This step verifies Inspector asset existence, correct CSS prefix usage, absence of Tailwind dependencies, Alpine.js auto-loading, and compatibility with both Luma and Hyvä themes.
• Updated the workflow summary to include confirmation that Inspector compatibility tests have passed.