Spider: Automatically reveal top cards

This matches basically all other Spider implementations I've played,
and makes playing much easier :)

I have left click-to-reveal in place, but mostly incase there is a
condition I've forgotten about.

Userland/Games/Spider/Game.cpp

@@ -114,6 +114,18 @@ void Game::draw_cards()
     update();
 }
 
+void Game::ensure_top_card_is_visible(NonnullRefPtr<CardStack> stack)
+{
+    if (stack->is_empty())
+        return;
+
+    auto& top_card = stack->peek();
+    if (top_card.is_upside_down()) {
+        top_card.set_upside_down(false);
+        update(top_card.rect());
+    }
+}
+
 void Game::detect_full_stacks()
 {
     auto& completed_stack = stack(Completed);
@@ -143,6 +155,8 @@ void Game::detect_full_stacks()
                     completed_stack.push(current_pile.pop());
                 }
 
+                ensure_top_card_is_visible(current_pile);
+
                 update_score(101);
             }
 
@@ -301,6 +315,8 @@ void Game::mouseup_event(GUI::MouseEvent& event)
 
                     detect_full_stacks();
 
+                    ensure_top_card_is_visible(*m_focused_stack);
+
                     rebound = false;
                     break;
                 }

Userland/Games/Spider/Game.h

@@ -67,6 +67,7 @@ private:
     void start_timer_if_necessary();
     void update_score(int delta);
     void draw_cards();
+    void ensure_top_card_is_visible(NonnullRefPtr<CardStack> stack);
     void detect_full_stacks();
     void detect_victory();