feat(core): card/pile conversion utils and GameMode-aware scoring (steps 2-prep, 5)

Step 2 prep — card_game dep + type-conversion utilities:
- Add card_game = "0.3.0" (registry Quaternions) to workspace + core
- suit_to_kl / suit_from_kl, rank_to_kl / rank_from_kl
- card_to_kl (drops id, Deck1), card_from_kl (reconstructs stable id
  from Clubs-first suit×13+rank ordering matching deck.rs)
- Ready to wire into KlondikeState pile projection once upstream
  adds KlondikeState::from_piles()

Step 5 — GameMode-aware scoring in the adapter:
- score_for_move_with_mode, score_for_flip_with_mode (return 0 in Zen)
- apply_undo_score (static, handles Zen + −15 penalty + clamp)
- score_for_recycle_with_mode (return 0 in Zen)
- game_state.rs: all inline GameMode::Zen checks replaced with
  adapter calls; adapter is now the single source of truth for
  "what score does this action give in this mode"

192 tests pass; clippy -D warnings clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_core/src/game_state.rs

@@ -275,11 +275,12 @@ impl GameState {
                 stock.cards.push(card);
             }
             self.recycle_count = self.recycle_count.saturating_add(1);
-            if self.mode != GameMode::Zen {
-                let penalty =
-                    KlondikeAdapter::score_for_recycle(self.recycle_count, self.draw_mode == DrawMode::DrawThree);
-                self.score = (self.score + penalty).max(0);
-            }
+            let penalty = KlondikeAdapter::score_for_recycle_with_mode(
+                self.recycle_count,
+                self.draw_mode == DrawMode::DrawThree,
+                self.mode,
+            );
+            self.score = (self.score + penalty).max(0);
             self.move_count = self.move_count.saturating_add(1);
             return Ok(());
         }
@@ -411,11 +412,7 @@ impl GameState {
             start
         };
 
-        let score_delta = if self.mode == GameMode::Zen {
-            0
-        } else {
-            self.adapter.score_for_move(&from, &to)
-        };
+        let score_delta = self.adapter.score_for_move_with_mode(&from, &to, self.mode);
         self.push_snapshot();
 
         // Execute move
@@ -446,8 +443,8 @@ impl GameState {
             .cards
             .append(&mut moved);
 
-        let flip_bonus = if flipped && self.mode != GameMode::Zen {
-            self.adapter.score_for_flip()
+        let flip_bonus = if flipped {
+            self.adapter.score_for_flip_with_mode(self.mode)
         } else {
             0
         };
@@ -478,11 +475,7 @@ impl GameState {
             .pop_back()
             .ok_or(MoveError::UndoStackEmpty)?;
         self.piles = snapshot.piles;
-        self.score = if self.mode == GameMode::Zen {
-            0
-        } else {
-            (snapshot.score + KlondikeAdapter::score_for_undo()).max(0)
-        };
+        self.score = KlondikeAdapter::apply_undo_score(snapshot.score, self.mode);
         self.move_count = snapshot.move_count;
         self.is_won = false;
         self.is_auto_completable = false;