fix(engine): toast on challenge exhaustion, block input during auto-complete (#71, #72)

- challenge_plugin: replace silent warn+return with InfoToast when all
  challenges are completed so the player gets clear feedback (#72)
- input_plugin: add AutoCompleteState guard to start_drag,
  touch_start_drag, and handle_double_tap so player input cannot race
  with the auto-complete move sequence (#71)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

solitaire_engine/src/challenge_plugin.rs

@@ -93,7 +93,9 @@ fn handle_start_challenge_request(
         return;
     }
     let Some(seed) = challenge_seed_for(progress.0.challenge_index) else {
-        warn!("challenge seed list is empty");
+        info_toast.write(InfoToastEvent(
+            "You've completed all challenges! More coming soon.".into(),
+        ));
         return;
     };
     new_game.write(NewGameRequestEvent {

solitaire_engine/src/input_plugin.rs

@@ -31,6 +31,7 @@ use solitaire_core::game_state::GameState;
 use solitaire_core::pile::PileType;
 use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
 
+use crate::auto_complete_plugin::AutoCompleteState;
 use crate::card_animation::tuning::AnimationTuning;
 use crate::card_animation::{CardAnimation, MotionCurve};
 use crate::card_plugin::{CardEntity, HintHighlight, HintHighlightTimer, STACK_FAN_FRAC};
@@ -572,6 +573,7 @@ fn start_drag(
     buttons: Res<ButtonInput<MouseButton>>,
     touches: Option<Res<Touches>>,
     paused: Option<Res<PausedResource>>,
+    auto_complete: Option<Res<AutoCompleteState>>,
     windows: Query<&Window, With<PrimaryWindow>>,
     cameras: Query<(&Camera, &GlobalTransform)>,
     layout: Option<Res<LayoutResource>>,
@@ -581,6 +583,9 @@ fn start_drag(
     if paused.is_some_and(|p| p.0) {
         return;
     }
+    if auto_complete.is_some_and(|ac| ac.active) {
+        return;
+    }
     // Only start a new drag when idle (no touch drag running either).
     if !buttons.just_pressed(MouseButton::Left) || !drag.is_idle() {
         return;
@@ -858,6 +863,7 @@ fn end_drag(
 fn touch_start_drag(
     mut touch_events: MessageReader<TouchInput>,
     paused: Option<Res<PausedResource>>,
+    auto_complete: Option<Res<AutoCompleteState>>,
     cameras: Query<(&Camera, &GlobalTransform)>,
     layout: Option<Res<LayoutResource>>,
     game: Res<GameStateResource>,
@@ -866,6 +872,9 @@ fn touch_start_drag(
     if paused.is_some_and(|p| p.0) {
         return;
     }
+    if auto_complete.is_some_and(|ac| ac.active) {
+        return;
+    }
     // Only one drag at a time.
     if !drag.is_idle() {
         return;
@@ -1503,6 +1512,7 @@ fn handle_double_tap(
     mut touch_events: MessageReader<TouchInput>,
     paused: Option<Res<PausedResource>>,
     radial: Option<Res<RightClickRadialState>>,
+    auto_complete: Option<Res<AutoCompleteState>>,
     drag: Res<DragState>,
     game: Res<GameStateResource>,
     settings: Option<Res<SettingsResource>>,
@@ -1522,6 +1532,10 @@ fn handle_double_tap(
     if radial.is_some_and(|r| r.is_active()) {
         return;
     }
+    // Auto-complete owns all moves during its sequence.
+    if auto_complete.is_some_and(|ac| ac.active) {
+        return;
+    }
 
     let Some(active_id) = drag.active_touch_id else {
         return;