feat(core): add pile, error, deck, rules, scoring modules with tests

Implements PileType/Pile, MoveError (thiserror), Deck with seeded shuffle,
deal_klondike layout, foundation/tableau placement rules, and Windows XP
Standard scoring — 41 tests, clippy clean.

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

solitaire_core/src/lib.rs

@@ -1 +1,6 @@
 pub mod card;
+pub mod deck;
+pub mod error;
+pub mod pile;
+pub mod rules;
+pub mod scoring;