A card can be shuffled into the deck because of a certain condition, and then that condition could cease to apply. If the card should not be presented to the player, it gets one last chance to hide.
There is currently no direct mechanism for making a card _already in the hand_ disappear if it is not relevant, although there are various ways to implement a Rule to do this.
This simulation engine is intended for people who are interested in game design, not computer programming -- the engine wants to do all the engine stuff so the simulation can be implemented with less familiarity with the language. Generics, however, are not widely regarded as a "new programmer" thing -- even though they're surprisingly familiar, in the end (slice-of-T, map-from-K-to-V). So a long comment explaining a bit about what's going on seems warranted.
InfoPanels are information displays that do not cost actions. One of them (the Prompt) is shown at the main menu; others can be made available as options in the menu, ether on an ongoing basis or for the current/next turn only.
Allow a pattern of multiple actions per turn. Card options can "refund" an action to the player if they should be free, or zero out the remaining actions if they should force the turn to go directly to the simulation step.
Deck does enough stuff it should be its own thing; its internal representation might change to make multiple insertions not quadratic, among other reasons. Currently it just does the obvious stuff, though. Allows inserting cards in random or specific slots and drawing cards. Shuffling a range of the deck comes later.
Add a callback to the Card interface to be invoked after an option is selected. This will most frequently be used for cards that always want to shuffle themselves back into the deck regardless of the Option selected.
Any RuleCollection change while the rule collection is running a turn is now delayed until all rules are evaluated. This gives consistent semantics for when rule changes invoked my rules themselves are applied.