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/klondike_adapter.rs

@@ -16,15 +16,6 @@ use klondike::{
 };
 use serde::{Deserialize, Serialize};
 
-/// Whether cards are drawn one at a time or three at a time from the stock.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-pub enum DrawMode {
-    /// Draw one card from stock per turn.
-    DrawOne,
-    /// Draw three cards from stock per turn; only the top is playable.
-    DrawThree,
-}
-
 /// Bridges `solitaire_core` game config and scoring to the upstream `klondike` crate.
 ///
 /// This type is intentionally zero-sized: it does not carry mutable runtime
@@ -35,12 +26,9 @@ pub struct KlondikeAdapter;
 
 impl KlondikeAdapter {
     /// Build a [`KlondikeConfig`] from draw mode and foundation house-rule setting.
-    pub fn config_for(draw_mode: DrawMode, take_from_foundation: bool) -> KlondikeConfig {
+    pub fn config_for(draw_mode: DrawStockConfig, take_from_foundation: bool) -> KlondikeConfig {
         KlondikeConfig {
-            draw_stock: match draw_mode {
-                DrawMode::DrawOne => DrawStockConfig::DrawOne,
-                DrawMode::DrawThree => DrawStockConfig::DrawThree,
-            },
+            draw_stock: draw_mode,
             move_from_foundation: if take_from_foundation {
                 MoveFromFoundationConfig::Allowed
             } else {