5.1.0 — Roster Groups & Mock Prefix Support

What's new

• getRosterGroups() — fetch all roster groups from JMRI
• getRosterEntriesByGroup(group) — fetch roster entries filtered to a specific group
• RosterGroup type exported from the package index

Mock mode

• Power state now tracked independently per connection prefix
• Throttle acquire reflects connection prefix in response data
• Roster mock data includes group membership (diesels, steam)