refactor(core): move solver to solitaire_data, DrawMode to klondike_adapter, remove pile/solver/schema_version

- Delete solitaire_core::solver — moved wholesale to solitaire_data::solver (re-exported at crate root)
- Delete solitaire_core::pile — no external users
- Move DrawMode from game_state to klondike_adapter; re-export as solitaire_core::DrawMode
- Remove schema_version field from GameState (redundant — deserializer stamps it from the constant)
- Update all callers across solitaire_data, solitaire_engine, solitaire_assetgen, solitaire_wasm

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

solitaire_engine/src/input_plugin.rs

@@ -52,7 +52,7 @@ use crate::settings_plugin::SettingsResource;
 use crate::time_attack_plugin::TimeAttackResource;
 use crate::touch_selection_plugin::TouchSelectionState;
 use crate::ui_theme::{MOTION_DRAG_REJECT_SECS, STATE_SUCCESS, STATE_WARNING};
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::DrawMode;
 
 /// System-set labels used to anchor external systems relative to the touch
 /// drag pipeline without duplicating the internal chain ordering.
@@ -79,13 +79,13 @@ fn dragged_card_z(index: usize) -> f32 {
 
 /// Solver budgets used by the H-key hint system.
 ///
-/// Wraps `solitaire_core::solver::SolverConfig` as a Bevy resource so
+/// Wraps `solitaire_data::solver::SolverConfig` as a Bevy resource so
 /// tests can inject tighter budgets to exercise the heuristic-fallback
 /// path. Production initialises this to `SolverConfig::default()` (100k
 /// move / 200k state budgets, the same numbers the new-game retry loop
 /// uses).
 #[derive(Resource, Debug, Clone, Default)]
-pub struct HintSolverConfig(pub solitaire_core::solver::SolverConfig);
+pub struct HintSolverConfig(pub solitaire_data::solver::SolverConfig);
 
 /// Registers keyboard, mouse, and touch input systems.
 ///
@@ -1789,7 +1789,7 @@ mod tests {
     use super::*;
     use crate::layout::compute_layout;
     use solitaire_core::{Foundation, Tableau};
-    use solitaire_core::game_state::{DrawMode, GameState};
+    use solitaire_core::{DrawMode, game_state::GameState};
 
     fn clear_test_piles(game: &mut GameState) {
         game.set_test_stock_cards(Vec::new());
@@ -2029,7 +2029,7 @@ mod tests {
     #[test]
     fn find_draggable_draw_three_waste_top_card_hit_at_fanned_position() {
         use solitaire_core::card::{Card, Rank, Suit};
-        use solitaire_core::game_state::{DrawMode, GameMode};
+        use solitaire_core::{DrawMode, game_state::GameMode};
         let mut game = GameState::new_with_mode(1, DrawMode::DrawThree, GameMode::Classic);
         // Three waste cards; top (id=202) is rightmost in the fan.
         game.set_test_waste_cards(vec![