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_engine/src/settings_plugin.rs

@@ -15,7 +15,7 @@ use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
 use bevy::prelude::*;
 use bevy::ui::{ComputedNode, UiGlobalTransform};
 use bevy::window::{WindowMoved, WindowResized};
-use solitaire_core::DrawMode;
+use solitaire_core::DrawStockConfig;
 use solitaire_data::{
     AnimSpeed, REPLAY_MOVE_INTERVAL_STEP_SECS, Settings, TIME_BONUS_MULTIPLIER_STEP,
     TOOLTIP_DELAY_STEP_SECS, WindowGeometry, load_settings_from, save_settings_to, settings::Theme,
@@ -1086,8 +1086,8 @@ fn handle_settings_buttons(
             }
             SettingsButton::ToggleDrawMode => {
                 settings.0.draw_mode = match settings.0.draw_mode {
-                    DrawMode::DrawOne => DrawMode::DrawThree,
-                    DrawMode::DrawThree => DrawMode::DrawOne,
+                    DrawStockConfig::DrawOne => DrawStockConfig::DrawThree,
+                    DrawStockConfig::DrawThree => DrawStockConfig::DrawOne,
                 };
                 persist(&path, &settings.0);
                 changed.write(SettingsChangedEvent(settings.0.clone()));
@@ -1310,10 +1310,10 @@ fn handle_sync_buttons(
     }
 }
 
-fn draw_mode_label(mode: &DrawMode) -> String {
+fn draw_mode_label(mode: &DrawStockConfig) -> String {
     match mode {
-        DrawMode::DrawOne => "Draw 1".into(),
-        DrawMode::DrawThree => "Draw 3".into(),
+        DrawStockConfig::DrawOne => "Draw 1".into(),
+        DrawStockConfig::DrawThree => "Draw 3".into(),
     }
 }