Fix return type in isInstalledShopOnsiteEligible() to ensure boolean

[manuelcanepa]

Description (*)

This pull request ensures the isInstalledShopOnsiteEligible method always returns a boolean value.

Previously, the method returned the raw configuration value, which may be a string or null. This change explicitly casts the return value to a boolean to prevent potential type mismatches and ensure consistent behavior across usages.

Fixed Issues (if relevant)

#106

Manual testing scenarios (*)

1. Ensure that the isInstalledShopOnsiteEligible method correctly returns true or false depending on the configuration value set in the backend.
2. Verify that all features relying on this method behave as expected without type warnings or logic inconsistencies.

Questions or comments

If this method is used in type-sensitive contexts (e.g., strict comparisons), this change guarantees proper behavior.

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)
• All automated tests passed successfully (all builds are green)