Allow Shuffling a Group of Selected Cards and Placing Them at the Top or Bottom of the Deck

[odama626]

Enable players to select a group of cards, shuffle them, and place the shuffled group either at the top or bottom of the library.

Acceptance Criteria:

Players can multi-select cards from any location (e.g., hand, battlefield, library, etc.).
Shuffled group can be placed at the top or bottom of the library.
Positioning respects library order (e.g., does not reveal the shuffle result).
Use Cases:

Triumph of Saint Katherine: Shuffle selected cards and place them at the top of the deck.
General card mechanics requiring controlled placement of shuffled groups.