fix(application): persist redirect value in setRedirect

[andrasbacsai]

Summary

• Fix General::setRedirect() to assign the selected Livewire redirect state to the Application model before saving.
• Preserve existing validation that blocks www redirect when no www domain is configured.
• Add ApplicationRedirectTest feature tests to verify:
• setRedirect persists a valid redirect change to the database.
• setRedirect dispatches an error and does not persist when www is selected without a matching domain.

Breaking Changes

• None.