refactor: replace local DrawMode with upstream klondike::DrawStockConfig (#82)

DrawMode was a 1:1 mirror of klondike::DrawStockConfig (DrawOne/DrawThree).
Delete it and use the upstream type everywhere; re-export DrawStockConfig from
solitaire_core. config_for assigns draw_stock directly and draw_mode() returns
session.config().inner.draw_stock.

Serde is unchanged — DrawStockConfig serialises to the same "DrawOne"/"DrawThree"
named variants, so persisted game_state.json / replay JSON stay byte-compatible
(no migration). Field/method/variable names containing draw_mode are unchanged.

35 files, mechanical type swap across all crates. Implemented via a multi-agent
workflow (core → per-crate consumers → verify). cargo test --workspace and
clippy --workspace --all-targets -- -D warnings green.

Closes #82

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

solitaire_core/src/lib.rs

@@ -13,8 +13,7 @@ pub mod klondike_adapter;
 // when decoding instructions to piles in `instruction_to_piles`) and do not
 // appear in any public method signature.
 pub use card_game::{Card, Session, SolveError};
-pub use klondike::{Foundation, Klondike, KlondikeInstruction, KlondikePile, Tableau};
-pub use klondike_adapter::DrawMode;
+pub use klondike::{DrawStockConfig, Foundation, Klondike, KlondikeInstruction, KlondikePile, Tableau};
 
 // Solvability check API (delegates to `card_game::Session::solve`); replaces the
 // former `solitaire_data::solver` wrapper module.