[SC] User Onboarding 3.4.5

Changes:

• Roadmap now stretches to the custom style’s available content width.
• Removed the add-on’s independent @xf-pageWidthMax restriction.
• ACP hero panel now uses neutral, native XenForo colors instead of the dark-blue gradient
• Minor Ui Improvement.
• Added a new “Register for [community name]” onboarding step for guests.
• Opens XenForo’s native registration page or overlay when selected.
• Controlled through the Unregistered / Unconfirmed user group permissions.
• Automatically hidden when new registrations are disabled.
• Guest activity is never stored as shared onboarding progress.
• Registered members automatically continue with the normal onboarding roadmap.
• Updated XenForo cron integration to use the correct _data/cron.xml format.
• Preserved existing User Onboarding maintenance scheduling.
• Updated add-on version to 3.3.3.
• General package cleanup and maintenance improvements.