change-sublist-to-observablecollection

What problem does it solve?

Converts List<T> sub-list properties in a master mente ViewModel to ObservableCollection<T> so that DataGrid row additions/deletions are properly notified to the View. Applies the ApplyFromCurrentEdit / SyncToCurrentEdit pattern used in ShukkaUriageInputViewModel.

Core Features & Use Cases

• Add an ObservableCollection field for sublists and expose an accompanying Edit* property for UI binding.
• Expand sublists from CurrentEdit on changes and clone items to enable safe editing without mutating the original data.
• Sync back to the List<T> before persisting (insert/update) to preserve data shape and support cancel/commit behavior.
• Bind the DataGrid to the ObservableCollection (EditSubItems) to ensure UI updates reflect additions and deletions immediately.

Quick Start

Bind the DataGrid to EditSubItems, and expose AddSubItem/DeleteSubItem commands to modify the collection; ensure CurrentEdit changes are mirrored into the observable list for UI notifications.