chore(deps): migrate to Bevy 0.17

- Event/EventReader/EventWriter renamed to Message/MessageReader/MessageWriter - add_event → add_message for all 67 call sites - ScrollPosition changed to tuple struct ScrollPosition(Vec2) - CursorIcon import moved from bevy::winit::cursor to bevy::window - WindowResolution::from((f32,f32)) removed — use (u32,u32) tuple - World::send_event → World::write_message in test code Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-28 13:04:44 -07:00
parent c8553dc8c5
commit 648cd44387
29 changed files with 1265 additions and 733 deletions
@@ -33,7 +33,7 @@ solitaire_sync   = { path = "solitaire_sync" }
 solitaire_data   = { path = "solitaire_data" }
 solitaire_engine = { path = "solitaire_engine" }
-bevy = "0.16"
+bevy = "0.17"
 kira = "0.9"
 axum               = "0.8"
@@ -21,7 +21,7 @@ fn main() {
            DefaultPlugins.set(WindowPlugin {
                primary_window: Some(Window {
                    title: "Solitaire Quest".into(),
-                    resolution: (1280.0, 800.0).into(),
+                    resolution: (1280u32, 800u32).into(),
                    ..default()
                }),
                ..default()
@@ -70,9 +70,9 @@ impl Plugin for AchievementPlugin {
        app.insert_resource(AchievementsResource(records))
            .insert_resource(AchievementsStoragePath(self.storage_path.clone()))
-            .add_event::<AchievementUnlockedEvent>()
+            .add_message::<AchievementUnlockedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
            // Run after GameMutation (so GameWonEvent is available), after
            // StatsUpdate (so stats reflect this win), and after ProgressUpdate
            // (so daily_challenge_streak is up to date for daily_devotee).
@@ -89,10 +89,10 @@ impl Plugin for AchievementPlugin {
 #[allow(clippy::too_many_arguments)]
 fn evaluate_on_win(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
-    mut unlocks: EventWriter<AchievementUnlockedEvent>,
+    mut unlocks: MessageWriter<AchievementUnlockedEvent>,
-    mut levelups: EventWriter<LevelUpEvent>,
+    mut levelups: MessageWriter<LevelUpEvent>,
-    mut xp_awarded: EventWriter<XpAwardedEvent>,
+    mut xp_awarded: MessageWriter<XpAwardedEvent>,
    game: Res<GameStateResource>,
    stats: Res<StatsResource>,
    path: Res<AchievementsStoragePath>,
@@ -398,7 +398,7 @@ mod tests {
        // StatsPlugin runs update_stats_on_win first (after GameMutation); that
        // bumps games_won to 1 before evaluate_on_win reads StatsResource.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 300,
        });
@@ -425,7 +425,7 @@ mod tests {
    fn repeated_win_does_not_refire_already_unlocked_achievement() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 300,
        });
@@ -436,7 +436,7 @@ mod tests {
            .resource_mut::<Events<AchievementUnlockedEvent>>()
            .clear();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 300,
        });
@@ -462,7 +462,7 @@ mod tests {
        let mut app = headless_app();
        // "no_undo" achievement awards BonusXp(25). Trigger it by sending a
        // GameWonEvent with undo_count == 0 (default) and enough stats to match.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 300,
        });
@@ -487,7 +487,7 @@ mod tests {
            .0
            .undo_count = 1;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 300,
        });
@@ -156,18 +156,18 @@ impl Plugin for AnimationPlugin {
        // Register the events this plugin consumes so tests that don't include
        // GamePlugin can still run AnimationPlugin in isolation. Double-registration
        // is idempotent in Bevy.
-        app.add_event::<GameWonEvent>()
+        app.add_message::<GameWonEvent>()
-            .add_event::<AchievementUnlockedEvent>()
+            .add_message::<AchievementUnlockedEvent>()
-            .add_event::<LevelUpEvent>()
+            .add_message::<LevelUpEvent>()
-            .add_event::<DailyChallengeCompletedEvent>()
+            .add_message::<DailyChallengeCompletedEvent>()
-            .add_event::<DailyGoalAnnouncementEvent>()
+            .add_message::<DailyGoalAnnouncementEvent>()
-            .add_event::<WeeklyGoalCompletedEvent>()
+            .add_message::<WeeklyGoalCompletedEvent>()
-            .add_event::<TimeAttackEndedEvent>()
+            .add_message::<TimeAttackEndedEvent>()
-            .add_event::<ChallengeAdvancedEvent>()
+            .add_message::<ChallengeAdvancedEvent>()
-            .add_event::<SettingsChangedEvent>()
+            .add_message::<SettingsChangedEvent>()
-            .add_event::<NewGameConfirmEvent>()
+            .add_message::<NewGameConfirmEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
            .init_resource::<EffectiveSlideDuration>()
            .init_resource::<ToastQueue>()
            .init_resource::<ActiveToast>()
@@ -207,7 +207,7 @@ fn init_slide_duration(
 }
 fn sync_slide_duration(
-    mut events: EventReader<SettingsChangedEvent>,
+    mut events: MessageReader<SettingsChangedEvent>,
    mut dur: ResMut<EffectiveSlideDuration>,
 ) {
    for ev in events.read() {
@@ -245,7 +245,7 @@ fn advance_card_anims(
 fn handle_win_cascade(
    mut commands: Commands,
-    mut events: EventReader<GameWonEvent>,
+    mut events: MessageReader<GameWonEvent>,
    cards: Query<(Entity, &Transform), With<CardEntity>>,
    layout: Option<Res<LayoutResource>>,
    settings: Option<Res<SettingsResource>>,
@@ -290,7 +290,7 @@ fn handle_win_cascade(
 fn handle_achievement_toast(
    mut commands: Commands,
-    mut events: EventReader<AchievementUnlockedEvent>,
+    mut events: MessageReader<AchievementUnlockedEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(
@@ -301,7 +301,7 @@ fn handle_achievement_toast(
    }
 }
-fn handle_levelup_toast(mut commands: Commands, mut events: EventReader<LevelUpEvent>) {
+fn handle_levelup_toast(mut commands: Commands, mut events: MessageReader<LevelUpEvent>) {
    for ev in events.read() {
        spawn_toast(
            &mut commands,
@@ -313,7 +313,7 @@ fn handle_levelup_toast(mut commands: Commands, mut events: EventReader<LevelUpE
 fn handle_daily_goal_announcement_toast(
    mut commands: Commands,
-    mut events: EventReader<DailyGoalAnnouncementEvent>,
+    mut events: MessageReader<DailyGoalAnnouncementEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(&mut commands, format!("Goal: {}", ev.0), DAILY_TOAST_SECS);
@@ -322,7 +322,7 @@ fn handle_daily_goal_announcement_toast(
 fn handle_daily_toast(
    mut commands: Commands,
-    mut events: EventReader<DailyChallengeCompletedEvent>,
+    mut events: MessageReader<DailyChallengeCompletedEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(
@@ -335,7 +335,7 @@ fn handle_daily_toast(
 fn handle_weekly_toast(
    mut commands: Commands,
-    mut events: EventReader<WeeklyGoalCompletedEvent>,
+    mut events: MessageReader<WeeklyGoalCompletedEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(
@@ -348,7 +348,7 @@ fn handle_weekly_toast(
 fn handle_time_attack_toast(
    mut commands: Commands,
-    mut events: EventReader<TimeAttackEndedEvent>,
+    mut events: MessageReader<TimeAttackEndedEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(
@@ -361,7 +361,7 @@ fn handle_time_attack_toast(
 fn handle_challenge_toast(
    mut commands: Commands,
-    mut events: EventReader<ChallengeAdvancedEvent>,
+    mut events: MessageReader<ChallengeAdvancedEvent>,
 ) {
    for ev in events.read() {
        spawn_toast(
@@ -374,7 +374,7 @@ fn handle_challenge_toast(
 fn handle_settings_toast(
    mut commands: Commands,
-    mut events: EventReader<SettingsChangedEvent>,
+    mut events: MessageReader<SettingsChangedEvent>,
    mut last_sfx: Local<Option<f32>>,
    mut last_music: Local<Option<f32>>,
 ) {
@@ -417,7 +417,7 @@ fn handle_auto_complete_toast(
 fn handle_new_game_confirm_toast(
    mut commands: Commands,
-    mut events: EventReader<NewGameConfirmEvent>,
+    mut events: MessageReader<NewGameConfirmEvent>,
 ) {
    for _ in events.read() {
        spawn_toast(&mut commands, "Press N again to start a new game".to_string(), 3.0);
@@ -430,7 +430,7 @@ fn handle_new_game_confirm_toast(
 /// decouples event production from rendering so multiple simultaneous events do
 /// not cause overlapping toast text on screen.
 fn enqueue_toasts(
-    mut events: EventReader<InfoToastEvent>,
+    mut events: MessageReader<InfoToastEvent>,
    mut queue: ResMut<ToastQueue>,
 ) {
    for ev in events.read() {
@@ -509,7 +509,7 @@ fn spawn_queued_toast(commands: &mut Commands, message: String) -> Entity {
        .id()
 }
-fn handle_xp_awarded_toast(mut commands: Commands, mut events: EventReader<XpAwardedEvent>) {
+fn handle_xp_awarded_toast(mut commands: Commands, mut events: MessageReader<XpAwardedEvent>) {
    for ev in events.read() {
        spawn_toast(&mut commands, format!("+{} XP", ev.amount), 3.0);
    }
@@ -709,7 +709,7 @@ mod tests {
        let mut app = App::new();
        app.add_plugins(MinimalPlugins).add_plugins(AnimationPlugin);
-        app.world_mut().send_event(InfoToastEvent("hello".to_string()));
+        app.world_mut().write_message(InfoToastEvent("hello".to_string()));
        app.update();
        let count = app
@@ -745,7 +745,7 @@ mod tests {
    fn toast_queue_enqueues_on_event() {
        let mut app = queue_app();
        app.world_mut()
-            .send_event(InfoToastEvent("test message".to_string()));
+            .write_message(InfoToastEvent("test message".to_string()));
        app.update();
        // After one update the message should have been consumed (shown) or is
        // still in the queue — either way we verify the system processed it by
@@ -776,7 +776,7 @@ mod tests {
        app.add_plugins(MinimalPlugins).add_plugins(AnimationPlugin);
        let fast_settings = Settings { animation_speed: AnimSpeed::Fast, ..Default::default() };
-        app.world_mut().send_event(SettingsChangedEvent(fast_settings));
+        app.world_mut().write_message(SettingsChangedEvent(fast_settings));
        app.update();
        let dur = app.world().resource::<EffectiveSlideDuration>().slide_secs;
@@ -795,7 +795,7 @@ mod tests {
        assert_eq!(before, 0, "no animations before win");
        app.world_mut()
-            .send_event(GameWonEvent { score: 500, time_seconds: 60 });
+            .write_message(GameWonEvent { score: 500, time_seconds: 60 });
        app.update();
        let after = app
@@ -130,15 +130,15 @@ impl Plugin for AudioPlugin {
            app.insert_resource(lib);
        }
-        app.add_event::<DrawRequestEvent>()
+        app.add_message::<DrawRequestEvent>()
-            .add_event::<MoveRequestEvent>()
+            .add_message::<MoveRequestEvent>()
-            .add_event::<MoveRejectedEvent>()
+            .add_message::<MoveRejectedEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<CardFlippedEvent>()
+            .add_message::<CardFlippedEvent>()
-            .add_event::<CardFaceRevealedEvent>()
+            .add_message::<CardFaceRevealedEvent>()
-            .add_event::<UndoRequestEvent>()
+            .add_message::<UndoRequestEvent>()
-            .add_event::<SettingsChangedEvent>()
+            .add_message::<SettingsChangedEvent>()
            .add_systems(Startup, apply_initial_volume)
            .add_systems(
                Update,
@@ -270,7 +270,7 @@ fn apply_initial_volume(
 }
 fn play_on_undo(
-    mut events: EventReader<UndoRequestEvent>,
+    mut events: MessageReader<UndoRequestEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -281,7 +281,7 @@ fn play_on_undo(
 }
 fn apply_volume_on_change(
-    mut events: EventReader<SettingsChangedEvent>,
+    mut events: MessageReader<SettingsChangedEvent>,
    mut audio: NonSendMut<AudioState>,
    mute: Option<Res<MuteState>>,
 ) {
@@ -326,7 +326,7 @@ fn handle_mute_keys(
 }
 fn play_on_draw(
-    mut events: EventReader<DrawRequestEvent>,
+    mut events: MessageReader<DrawRequestEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
    game: Option<Res<GameStateResource>>,
@@ -361,7 +361,7 @@ fn play_on_draw(
 }
 fn play_on_move(
-    mut events: EventReader<MoveRequestEvent>,
+    mut events: MessageReader<MoveRequestEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -374,7 +374,7 @@ fn play_on_move(
 }
 fn play_on_rejected(
-    mut events: EventReader<MoveRejectedEvent>,
+    mut events: MessageReader<MoveRejectedEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -387,7 +387,7 @@ fn play_on_rejected(
 }
 fn play_on_new_game(
-    mut events: EventReader<NewGameRequestEvent>,
+    mut events: MessageReader<NewGameRequestEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -400,7 +400,7 @@ fn play_on_new_game(
 }
 fn play_on_win(
-    mut events: EventReader<GameWonEvent>,
+    mut events: MessageReader<GameWonEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -418,7 +418,7 @@ fn play_on_win(
 /// Driven by `CardFaceRevealedEvent`, which is fired by `tick_flip_anim` at
 /// the phase transition (scale.x crosses 0), not by the move event itself.
 fn play_on_face_revealed(
-    mut events: EventReader<CardFaceRevealedEvent>,
+    mut events: MessageReader<CardFaceRevealedEvent>,
    mut audio: NonSendMut<AudioState>,
    lib: Option<Res<SoundLibrary>>,
 ) {
@@ -57,7 +57,7 @@ impl Plugin for AutoCompletePlugin {
 fn detect_auto_complete(
    mut state: ResMut<AutoCompleteState>,
    game: Res<GameStateResource>,
-    mut changed: EventReader<StateChangedEvent>,
+    mut changed: MessageReader<StateChangedEvent>,
 ) {
    // Only re-evaluate on state changes to avoid per-frame allocations.
    if changed.is_empty() && !game.is_changed() {
@@ -106,7 +106,7 @@ fn drive_auto_complete(
    mut state: ResMut<AutoCompleteState>,
    game: Res<GameStateResource>,
    time: Res<Time>,
-    mut moves: EventWriter<MoveRequestEvent>,
+    mut moves: MessageWriter<MoveRequestEvent>,
 ) {
    if !state.active {
        return;
@@ -176,7 +176,7 @@ mod tests {
        let mut app = headless_app();
        // Install a nearly-won state and fire StateChangedEvent.
        app.world_mut().resource_mut::<GameStateResource>().0 = nearly_won_state();
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        assert!(app.world().resource::<AutoCompleteState>().active);
@@ -186,7 +186,7 @@ mod tests {
    fn drive_fires_move_request_when_active() {
        let mut app = headless_app();
        app.world_mut().resource_mut::<GameStateResource>().0 = nearly_won_state();
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update(); // detect runs, sets active
        app.update(); // drive fires the move
@@ -206,7 +206,7 @@ mod tests {
        let mut gs = nearly_won_state();
        gs.is_won = true;
        app.world_mut().resource_mut::<GameStateResource>().0 = gs;
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        assert!(!app.world().resource::<AutoCompleteState>().active);
@@ -227,9 +227,9 @@ pub(crate) fn apply_drag_visual(
 pub(crate) fn drain_input_buffer(
    mut buffer: ResMut<InputBuffer>,
    anims: Query<&CardAnimation>,
-    mut move_events: EventWriter<MoveRequestEvent>,
+    mut move_events: MessageWriter<MoveRequestEvent>,
-    mut draw_events: EventWriter<DrawRequestEvent>,
+    mut draw_events: MessageWriter<DrawRequestEvent>,
-    mut undo_events: EventWriter<UndoRequestEvent>,
+    mut undo_events: MessageWriter<UndoRequestEvent>,
 ) {
    if !anims.is_empty() {
        return;
@@ -111,10 +111,10 @@ impl Plugin for CardAnimationPlugin {
    fn build(&self, app: &mut App) {
        // Register events and resources that interaction systems depend on,
        // idempotently — double-registration is safe in Bevy.
-        app.add_event::<MoveRequestEvent>()
+        app.add_message::<MoveRequestEvent>()
-            .add_event::<DrawRequestEvent>()
+            .add_message::<DrawRequestEvent>()
-            .add_event::<UndoRequestEvent>()
+            .add_message::<UndoRequestEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
            .init_resource::<DragState>()
            .init_resource::<HoverState>()
            .init_resource::<InputBuffer>()
@@ -163,7 +163,7 @@ impl Plugin for WinCascadePlugin {
 /// Cards scatter to 8 off-screen positions with per-card stagger. The z-lift
 /// creates a "burst" effect as cards fly outward.
 fn trigger_expressive_win_cascade(
-    mut events: EventReader<GameWonEvent>,
+    mut events: MessageReader<GameWonEvent>,
    cards: Query<(Entity, &Transform), With<CardEntity>>,
    layout: Option<Res<LayoutResource>>,
    mut commands: Commands,
@@ -157,9 +157,9 @@ impl Plugin for CardPlugin {
        // `MinimalPlugins` (tests) this resource is absent by default, so we
        // ensure it exists here. Under `DefaultPlugins` the call is a no-op.
        app.init_resource::<ButtonInput<MouseButton>>()
-            .add_event::<SettingsChangedEvent>()
+            .add_message::<SettingsChangedEvent>()
-            .add_event::<CardFlippedEvent>()
+            .add_message::<CardFlippedEvent>()
-            .add_event::<CardFaceRevealedEvent>()
+            .add_message::<CardFaceRevealedEvent>()
            .add_systems(PostStartup, (sync_cards_startup, update_stock_empty_indicator_startup))
            .add_systems(
                Update,
@@ -183,8 +183,8 @@ impl Plugin for CardPlugin {
 /// When card-back selection changes in Settings, re-render all cards so the
 /// new back colour is applied immediately (without waiting for a state change).
 fn resync_cards_on_settings_change(
-    mut setting_events: EventReader<SettingsChangedEvent>,
+    mut setting_events: MessageReader<SettingsChangedEvent>,
-    mut state_events: EventWriter<StateChangedEvent>,
+    mut state_events: MessageWriter<StateChangedEvent>,
 ) {
    if setting_events.read().next().is_some() {
        state_events.write(StateChangedEvent);
@@ -213,7 +213,7 @@ fn sync_cards_startup(
 }
 fn sync_cards_on_change(
-    mut events: EventReader<StateChangedEvent>,
+    mut events: MessageReader<StateChangedEvent>,
    commands: Commands,
    game: Res<GameStateResource>,
    layout: Option<Res<LayoutResource>>,
@@ -508,7 +508,7 @@ fn label_visibility(card: &Card) -> Visibility {
 ///
 /// Skipped when `EffectiveSlideDuration::slide_secs == 0.0` (Instant speed).
 fn start_flip_anim(
-    mut events: EventReader<CardFlippedEvent>,
+    mut events: MessageReader<CardFlippedEvent>,
    slide_dur: Option<Res<EffectiveSlideDuration>>,
    mut commands: Commands,
    card_entities: Query<(Entity, &CardEntity)>,
@@ -543,7 +543,7 @@ fn tick_flip_anim(
    mut commands: Commands,
    time: Res<Time>,
    mut anims: Query<(Entity, &CardEntity, &mut Transform, &mut CardFlipAnim)>,
-    mut reveal_events: EventWriter<CardFaceRevealedEvent>,
+    mut reveal_events: MessageWriter<CardFaceRevealedEvent>,
 ) {
    let dt = time.delta_secs();
    for (entity, card_entity, mut transform, mut anim) in &mut anims {
@@ -742,7 +742,7 @@ fn clear_right_click_highlights(
 ///
 /// This ensures stale highlights do not linger after a card is moved.
 fn clear_right_click_highlights_on_state_change(
-    mut events: EventReader<StateChangedEvent>,
+    mut events: MessageReader<StateChangedEvent>,
    mut commands: Commands,
    highlighted: Query<Entity, With<RightClickHighlight>>,
    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
@@ -980,7 +980,7 @@ fn update_stock_empty_indicator_startup(
 /// Runs each `Update` tick when a `StateChangedEvent` arrives, keeping the
 /// stock pile marker dim state and "↺" label in sync with the current stock.
 fn update_stock_empty_indicator(
-    mut events: EventReader<StateChangedEvent>,
+    mut events: MessageReader<StateChangedEvent>,
    mut commands: Commands,
    game: Res<GameStateResource>,
    layout: Option<Res<LayoutResource>>,
@@ -1106,7 +1106,7 @@ mod tests {
        let mut app = app();
        // Trigger a draw, which moves a card from stock to waste and should
        // flip it face-up. Count visible labels after.
-        app.world_mut().send_event(crate::events::DrawRequestEvent);
+        app.world_mut().write_message(crate::events::DrawRequestEvent);
        app.update();
        // Now 1 card in waste (face-up), 23 in stock (face-down). So 24
        // hidden labels total in stock, plus 21 in tableau = 44.
@@ -18,7 +18,7 @@ pub const CHALLENGE_UNLOCK_LEVEL: u32 = 5;
 /// Fired when the player has just completed a Challenge-mode game and the
 /// `challenge_index` cursor advances.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct ChallengeAdvancedEvent {
    pub previous_index: u32,
    pub new_index: u32,
@@ -28,10 +28,10 @@ pub struct ChallengePlugin;
 impl Plugin for ChallengePlugin {
    fn build(&self, app: &mut App) {
-        app.add_event::<ChallengeAdvancedEvent>()
+        app.add_message::<ChallengeAdvancedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
            // Run after ProgressUpdate so we don't fight ProgressPlugin's add_xp.
            .add_systems(Update, advance_on_challenge_win.after(ProgressUpdate))
            .add_systems(Update, handle_start_challenge_request.before(GameMutation));
@@ -39,12 +39,12 @@ impl Plugin for ChallengePlugin {
 }
 fn advance_on_challenge_win(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
    game: Res<GameStateResource>,
    mut progress: ResMut<ProgressResource>,
    path: Res<ProgressStoragePath>,
-    mut advanced: EventWriter<ChallengeAdvancedEvent>,
+    mut advanced: MessageWriter<ChallengeAdvancedEvent>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    for _ in wins.read() {
        if game.0.mode != GameMode::Challenge {
@@ -70,8 +70,8 @@ fn advance_on_challenge_win(
 fn handle_start_challenge_request(
    keys: Res<ButtonInput<KeyCode>>,
    progress: Res<ProgressResource>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
-    mut info_toast: EventWriter<InfoToastEvent>,
+    mut info_toast: MessageWriter<InfoToastEvent>,
 ) {
    if !keys.just_pressed(KeyCode::KeyX) {
        return;
@@ -124,7 +124,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 100,
        });
@@ -145,7 +145,7 @@ mod tests {
    fn classic_win_does_not_advance_challenge_index() {
        let mut app = headless_app();
        // Default GameStateResource is Classic mode.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 100,
        });
@@ -211,7 +211,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 100,
        });
@@ -231,7 +231,7 @@ mod tests {
    fn classic_win_does_not_fire_challenge_complete_toast() {
        let mut app = headless_app();
        // Default mode is Classic.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 100,
        });
@@ -12,8 +12,7 @@
 //!   The tint is cleared to default the frame the drag ends.
 use bevy::prelude::*;
-use bevy::window::{PrimaryWindow, SystemCursorIcon};
+use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
 use bevy::winit::cursor::CursorIcon;
 use solitaire_core::card::Suit;
 use solitaire_core::game_state::{DrawMode, GameState};
 use solitaire_core::pile::PileType;
@@ -43,7 +43,7 @@ pub struct DailyChallengeResource {
 /// Fired when the player presses C to start the daily challenge.
 /// Carries the current goal description so it can be displayed as a toast.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct DailyGoalAnnouncementEvent(pub String);
 impl DailyChallengeResource {
@@ -60,7 +60,7 @@ impl DailyChallengeResource {
 }
 /// Fired when the player has just completed today's daily challenge.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct DailyChallengeCompletedEvent {
    pub date: NaiveDate,
    pub streak: u32,
@@ -77,11 +77,11 @@ impl Plugin for DailyChallengePlugin {
    fn build(&self, app: &mut App) {
        app.insert_resource(DailyChallengeResource::for_today())
            .init_resource::<DailyChallengeTask>()
-            .add_event::<DailyChallengeCompletedEvent>()
+            .add_message::<DailyChallengeCompletedEvent>()
-            .add_event::<DailyGoalAnnouncementEvent>()
+            .add_message::<DailyGoalAnnouncementEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
            .add_systems(Startup, fetch_server_challenge)
            .add_systems(Update, poll_server_challenge)
            // record/award after the base ProgressUpdate so we don't fight
@@ -145,14 +145,14 @@ fn poll_server_challenge(
 #[allow(clippy::too_many_arguments)]
 fn handle_daily_completion(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
    daily: Res<DailyChallengeResource>,
    game: Res<GameStateResource>,
    mut progress: ResMut<ProgressResource>,
    path: Res<ProgressStoragePath>,
-    mut completed: EventWriter<DailyChallengeCompletedEvent>,
+    mut completed: MessageWriter<DailyChallengeCompletedEvent>,
-    mut xp_awarded: EventWriter<XpAwardedEvent>,
+    mut xp_awarded: MessageWriter<XpAwardedEvent>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    for ev in wins.read() {
        if game.0.seed != daily.seed {
@@ -191,8 +191,8 @@ fn handle_daily_completion(
 fn handle_start_daily_request(
    keys: Res<ButtonInput<KeyCode>>,
    daily: Res<DailyChallengeResource>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
-    mut announce: EventWriter<DailyGoalAnnouncementEvent>,
+    mut announce: MessageWriter<DailyGoalAnnouncementEvent>,
 ) {
    if keys.just_pressed(KeyCode::KeyC) {
        new_game.write(NewGameRequestEvent {
@@ -244,7 +244,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new(daily_seed, DrawMode::DrawOne);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -270,7 +270,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new(daily_seed.wrapping_add(7777), DrawMode::DrawOne);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -291,13 +291,13 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new(daily_seed, DrawMode::DrawOne);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
        app.update();
        // Re-send win.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -1,13 +1,13 @@
 //! Cross-system events used by the engine's plugins.
-use bevy::prelude::Event;
+use bevy::prelude::Message;
 use solitaire_core::game_state::GameMode;
 use solitaire_core::pile::PileType;
 use solitaire_data::AchievementRecord;
 /// Request to move `count` cards from `from` to `to`. Fired by input systems,
 /// consumed by `GamePlugin`.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct MoveRequestEvent {
    pub from: PileType,
    pub to: PileType,
@@ -15,16 +15,16 @@ pub struct MoveRequestEvent {
 }
 /// Request to draw from the stock (or recycle waste when stock is empty).
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct DrawRequestEvent;
 /// Request to undo the most recent state change.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct UndoRequestEvent;
 /// Request to start a new game. `seed = None` uses a system-time seed.
 /// `mode = None` reuses the current game's `GameMode`.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct NewGameRequestEvent {
    pub seed: Option<u64>,
    pub mode: Option<GameMode>,
@@ -32,13 +32,13 @@ pub struct NewGameRequestEvent {
 /// Fired by `GamePlugin` after any successful state mutation. Rendering and
 /// score-display systems listen for this to refresh.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct StateChangedEvent;
 /// Fired by input/UI systems when a player attempts to drop dragged cards
 /// on a real pile but the move violates the rules. Drives the
 /// `card_invalid.wav` SFX. Not fired for drops in empty space.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct MoveRejectedEvent {
    pub from: PileType,
    pub to: PileType,
@@ -46,14 +46,14 @@ pub struct MoveRejectedEvent {
 }
 /// Fired once when the active game transitions to won.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct GameWonEvent {
    pub score: i32,
    pub time_seconds: u64,
 }
 /// Fired when a card's face-up state changes during gameplay.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct CardFlippedEvent(pub u32);
 /// Fired by the flip animation at its midpoint — the instant the card face
@@ -62,37 +62,37 @@ pub struct CardFlippedEvent(pub u32);
 /// Audio systems should listen to this event rather than `CardFlippedEvent`
 /// so the flip sound is synchronised with the visual reveal, not the move
 /// that triggered the animation.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct CardFaceRevealedEvent(pub u32);
 /// Achievement unlocked notification carrying the full `AchievementRecord` for
 /// the newly unlocked achievement. Consumed by the toast renderer and any
 /// persistence/UI systems that need unlock metadata.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct AchievementUnlockedEvent(pub AchievementRecord);
 /// Request to manually trigger a sync pull from the active backend.
 ///
 /// Fired by the Settings panel "Sync Now" button. `SyncPlugin` responds by
 /// starting a new pull task if one is not already in flight.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct ManualSyncRequestEvent;
 /// Fired by `InputPlugin` when N is pressed while a game is in progress
 /// but confirmation has not yet been received. The animation plugin shows
 /// a "Press N again to confirm" toast. A second N press within the
 /// confirmation window sends `NewGameRequestEvent`.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct NewGameConfirmEvent;
 /// Generic informational toast message. Any system can fire this to display
 /// a short string to the player, e.g. "Locked — reach level 5".
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct InfoToastEvent(pub String);
 /// Fired by `ProgressPlugin` immediately after awarding XP for a win so the
 /// animation layer can display a "+N XP" toast alongside the win cascade.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct XpAwardedEvent {
    pub amount: u64,
 }
@@ -100,7 +100,7 @@ pub struct XpAwardedEvent {
 /// Fired by `InputPlugin` when the player presses G to forfeit the current
 /// game. Consumed by `StatsPlugin` which records the abandoned game,
 /// persists stats, and starts a fresh deal.
-#[derive(Event, Debug, Clone, Copy, Default)]
+#[derive(Message, Debug, Clone, Copy, Default)]
 pub struct ForfeitEvent;
 /// Fired when the player requests a hint (H key). Carries the source card ID
@@ -108,7 +108,7 @@ pub struct ForfeitEvent;
 ///
 /// Consumed by `CardPlugin` (to apply `HintHighlight` on the card entity) and
 /// `TablePlugin` (to tint the destination `PileMarker` gold for 2 s).
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct HintVisualEvent {
    /// The `Card::id` of the source card to be highlighted.
    pub source_card_id: u32,
@@ -184,7 +184,7 @@ impl Plugin for FeedbackAnimPlugin {
 /// Inserts `ShakeAnim` on all card entities belonging to the destination pile
 /// when a `MoveRejectedEvent` fires.
 fn start_shake_anim(
-    mut events: EventReader<MoveRejectedEvent>,
+    mut events: MessageReader<MoveRejectedEvent>,
    game: Res<GameStateResource>,
    card_entities: Query<(Entity, &CardEntity, &Transform)>,
    mut commands: Commands,
@@ -243,7 +243,7 @@ fn tick_shake_anim(
 /// Inserts `SettleAnim` on the top card of every non-empty pile when
 /// `StateChangedEvent` fires.
 fn start_settle_anim(
-    mut events: EventReader<StateChangedEvent>,
+    mut events: MessageReader<StateChangedEvent>,
    game: Res<GameStateResource>,
    card_entities: Query<(Entity, &CardEntity)>,
    mut commands: Commands,
@@ -304,7 +304,7 @@ fn tick_settle_anim(
 /// and fires the deal animation for every card entity currently in the world.
 /// The stagger is looked up from `SettingsResource` via `deal_stagger_secs_for_speed`.
 fn start_deal_anim(
-    mut events: EventReader<NewGameRequestEvent>,
+    mut events: MessageReader<NewGameRequestEvent>,
    layout: Option<Res<LayoutResource>>,
    game: Res<GameStateResource>,
    settings: Option<Res<SettingsResource>>,
@@ -71,16 +71,16 @@ impl Plugin for GamePlugin {
            .insert_resource(GameStatePath(path))
            .init_resource::<DragState>()
            .init_resource::<SyncStatusResource>()
-            .add_event::<MoveRequestEvent>()
+            .add_message::<MoveRequestEvent>()
-            .add_event::<DrawRequestEvent>()
+            .add_message::<DrawRequestEvent>()
-            .add_event::<UndoRequestEvent>()
+            .add_message::<UndoRequestEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<StateChangedEvent>()
+            .add_message::<StateChangedEvent>()
-            .add_event::<crate::events::MoveRejectedEvent>()
+            .add_message::<crate::events::MoveRejectedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<crate::events::CardFlippedEvent>()
+            .add_message::<crate::events::CardFlippedEvent>()
-            .add_event::<crate::events::AchievementUnlockedEvent>()
+            .add_message::<crate::events::AchievementUnlockedEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
            .add_systems(
                Update,
                (
@@ -152,9 +152,9 @@ fn seed_from_system_time() -> u64 {
 #[allow(clippy::too_many_arguments)]
 fn handle_new_game(
    mut commands: Commands,
-    mut new_game: EventReader<NewGameRequestEvent>,
+    mut new_game: MessageReader<NewGameRequestEvent>,
    mut game: ResMut<GameStateResource>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
    settings: Option<Res<crate::settings_plugin::SettingsResource>>,
    path: Option<Res<GameStatePath>>,
    confirm_screens: Query<Entity, With<ConfirmNewGameScreen>>,
@@ -287,7 +287,7 @@ fn handle_confirm_input(
    mut commands: Commands,
    keys: Option<Res<ButtonInput<KeyCode>>>,
    screens: Query<(Entity, &OriginalNewGameRequest), With<ConfirmNewGameScreen>>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
 ) {
    let Ok((entity, original)) = screens.single() else {
        return;
@@ -314,10 +314,10 @@ fn handle_confirm_input(
 }
 fn handle_draw(
-    mut draws: EventReader<DrawRequestEvent>,
+    mut draws: MessageReader<DrawRequestEvent>,
    mut game: ResMut<GameStateResource>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
-    mut flipped: EventWriter<CardFlippedEvent>,
+    mut flipped: MessageWriter<CardFlippedEvent>,
 ) {
    use solitaire_core::pile::PileType;
@@ -357,11 +357,11 @@ fn handle_draw(
 }
 fn handle_move(
-    mut moves: EventReader<MoveRequestEvent>,
+    mut moves: MessageReader<MoveRequestEvent>,
    mut game: ResMut<GameStateResource>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
-    mut won: EventWriter<GameWonEvent>,
+    mut won: MessageWriter<GameWonEvent>,
-    mut flipped: EventWriter<crate::events::CardFlippedEvent>,
+    mut flipped: MessageWriter<crate::events::CardFlippedEvent>,
    path: Option<Res<GameStatePath>>,
 ) {
    for ev in moves.read() {
@@ -408,10 +408,10 @@ fn handle_move(
 }
 fn handle_undo(
-    mut undos: EventReader<UndoRequestEvent>,
+    mut undos: MessageReader<UndoRequestEvent>,
    mut game: ResMut<GameStateResource>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    use solitaire_core::error::MoveError;
@@ -500,9 +500,9 @@ pub fn has_legal_moves(game: &GameState) -> bool {
 /// game is won.
 fn check_no_moves(
    mut commands: Commands,
-    mut events: EventReader<StateChangedEvent>,
+    mut events: MessageReader<StateChangedEvent>,
    game: Res<GameStateResource>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
    mut already_fired: Local<bool>,
    game_over_screens: Query<Entity, With<GameOverScreen>>,
 ) {
@@ -628,8 +628,8 @@ fn handle_game_over_input(
    mut commands: Commands,
    keys: Option<Res<ButtonInput<KeyCode>>>,
    screens: Query<Entity, With<GameOverScreen>>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
-    mut undo: EventWriter<UndoRequestEvent>,
+    mut undo: MessageWriter<UndoRequestEvent>,
 ) {
    if screens.is_empty() {
        return;
@@ -685,7 +685,7 @@ fn auto_save_game_state(
 /// `save_game_state_to` helper skips them). Blocking on exit is acceptable
 /// because the game loop is already shutting down.
 fn save_game_state_on_exit(
-    mut exit_events: EventReader<AppExit>,
+    mut exit_events: MessageReader<AppExit>,
    game: Res<GameStateResource>,
    path: Res<GameStatePath>,
 ) {
@@ -739,7 +739,7 @@ mod tests {
            .cards
            .len();
-        app.world_mut().send_event(DrawRequestEvent);
+        app.world_mut().write_message(DrawRequestEvent);
        app.update();
        let stock_after = app
@@ -763,7 +763,7 @@ mod tests {
    #[test]
    fn draw_request_fires_state_changed_event() {
        let mut app = test_app(42);
-        app.world_mut().send_event(DrawRequestEvent);
+        app.world_mut().write_message(DrawRequestEvent);
        app.update();
        let events = app.world().resource::<Events<StateChangedEvent>>();
        let mut reader = events.get_cursor();
@@ -773,9 +773,9 @@ mod tests {
    #[test]
    fn undo_after_draw_restores_state() {
        let mut app = test_app(42);
-        app.world_mut().send_event(DrawRequestEvent);
+        app.world_mut().write_message(DrawRequestEvent);
        app.update();
-        app.world_mut().send_event(UndoRequestEvent);
+        app.world_mut().write_message(UndoRequestEvent);
        app.update();
        let g = &app.world().resource::<GameStateResource>().0;
        assert_eq!(g.piles[&PileType::Stock].cards.len(), 24);
@@ -795,7 +795,7 @@ mod tests {
            .map(|c| c.id)
            .collect();
-        app.world_mut().send_event(NewGameRequestEvent { seed: Some(999), mode: None });
+        app.world_mut().write_message(NewGameRequestEvent { seed: Some(999), mode: None });
        app.update();
        let after: Vec<u32> = app
@@ -858,7 +858,7 @@ mod tests {
    fn invalid_move_does_not_fire_state_changed() {
        let mut app = test_app(42);
        // Stock -> Waste is InvalidDestination; no state change expected.
-        app.world_mut().send_event(MoveRequestEvent {
+        app.world_mut().write_message(MoveRequestEvent {
            from: PileType::Stock,
            to: PileType::Waste,
            count: 1,
@@ -892,7 +892,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new(7654, DrawMode::DrawOne);
-        app.world_mut().send_event(AppExit::Success);
+        app.world_mut().write_message(AppExit::Success);
        app.update();
        let loaded = load_game_state_from(&path).expect("file should exist after exit");
@@ -913,7 +913,7 @@ mod tests {
        let mut app = test_app(1);
        app.insert_resource(GameStatePath(Some(path.clone())));
-        app.world_mut().send_event(NewGameRequestEvent { seed: Some(2), mode: None });
+        app.world_mut().write_message(NewGameRequestEvent { seed: Some(2), mode: None });
        app.update();
        assert!(!path.exists(), "saved file should be deleted after new game");
@@ -949,7 +949,7 @@ mod tests {
            t.cards.push(Card { id: 902, suit: Suit::Clubs, rank: Rank::King, face_up: true });
        }
-        app.world_mut().send_event(MoveRequestEvent {
+        app.world_mut().write_message(MoveRequestEvent {
            from: PileType::Tableau(0),
            to: PileType::Tableau(1),
            count: 1,
@@ -1035,7 +1035,7 @@ mod tests {
                .push(Card { id: 912, suit: Suit::Spades, rank: Rank::King, face_up: true });
        }
-        app.world_mut().send_event(MoveRequestEvent {
+        app.world_mut().write_message(MoveRequestEvent {
            from: PileType::Tableau(0),
            to: PileType::Tableau(1),
            count: 1,
@@ -1125,7 +1125,7 @@ mod tests {
        // Simulate an active game with moves made.
        app.world_mut().resource_mut::<GameStateResource>().0.move_count = 5;
        app.world_mut()
-            .send_event(NewGameRequestEvent { seed: None, mode: None });
+            .write_message(NewGameRequestEvent { seed: None, mode: None });
        app.update();
        let count = app
@@ -1146,7 +1146,7 @@ mod tests {
            "test assumes a fresh game with no moves"
        );
        app.world_mut()
-            .send_event(NewGameRequestEvent { seed: None, mode: None });
+            .write_message(NewGameRequestEvent { seed: None, mode: None });
        app.update();
        let count = app
@@ -1165,7 +1165,7 @@ mod tests {
    fn game_over_screen_absent_when_moves_available() {
        // A fresh game always has moves (stock is non-empty).
        let mut app = test_app_with_input(42);
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        let count = app
@@ -1201,7 +1201,7 @@ mod tests {
            });
        }
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        let count = app
@@ -1240,7 +1240,7 @@ mod tests {
            });
        }
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        // Collect all Text values that are children of the GameOverScreen entity tree.
@@ -1295,7 +1295,7 @@ mod tests {
                face_up: true,
            });
        }
-        app.world_mut().send_event(StateChangedEvent);
+        app.world_mut().write_message(StateChangedEvent);
        app.update();
        // Confirm the overlay is present.
@@ -1338,7 +1338,7 @@ mod tests {
    fn undo_on_empty_stack_fires_info_toast() {
        let mut app = test_app(42);
        // Fresh game — undo stack is empty, so undo() returns UndoStackEmpty.
-        app.world_mut().send_event(UndoRequestEvent);
+        app.world_mut().write_message(UndoRequestEvent);
        app.update();
        let events = app.world().resource::<Events<InfoToastEvent>>();
@@ -1357,12 +1357,12 @@ mod tests {
    fn undo_after_draw_does_not_fire_info_toast() {
        let mut app = test_app(42);
        // Make a move so the undo stack is non-empty.
-        app.world_mut().send_event(DrawRequestEvent);
+        app.world_mut().write_message(DrawRequestEvent);
        app.update();
        // Clear events from the draw so we start with a clean slate.
        app.world_mut().resource_mut::<Events<InfoToastEvent>>().clear();
-        app.world_mut().send_event(UndoRequestEvent);
+        app.world_mut().write_message(UndoRequestEvent);
        app.update();
        let events = app.world().resource::<Events<InfoToastEvent>>();
@@ -475,7 +475,7 @@ fn update_selection_hud(
 /// to debounce so the toast only appears on the leading edge.
 fn announce_auto_complete(
    auto_complete: Option<Res<AutoCompleteState>>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
    mut was_active: Local<bool>,
 ) {
    let now_active = auto_complete.as_ref().is_some_and(|ac| ac.active);
@@ -58,10 +58,10 @@ pub struct InputPlugin;
 impl Plugin for InputPlugin {
    fn build(&self, app: &mut App) {
        app.init_resource::<HintCycleIndex>()
-            .add_event::<NewGameConfirmEvent>()
+            .add_message::<NewGameConfirmEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
-            .add_event::<ForfeitEvent>()
+            .add_message::<ForfeitEvent>()
-            .add_event::<HintVisualEvent>()
+            .add_message::<HintVisualEvent>()
            .add_systems(
                Update,
                (
@@ -89,13 +89,13 @@ const FORFEIT_CONFIRM_WINDOW: f32 = 3.0;
 /// within Bevy's 16-parameter limit.
 #[derive(SystemParam)]
 struct KeyboardEvents<'w> {
-    undo: EventWriter<'w, UndoRequestEvent>,
+    undo: MessageWriter<'w, UndoRequestEvent>,
-    new_game: EventWriter<'w, NewGameRequestEvent>,
+    new_game: MessageWriter<'w, NewGameRequestEvent>,
-    confirm_event: EventWriter<'w, NewGameConfirmEvent>,
+    confirm_event: MessageWriter<'w, NewGameConfirmEvent>,
-    info_toast: EventWriter<'w, InfoToastEvent>,
+    info_toast: MessageWriter<'w, InfoToastEvent>,
-    draw: EventWriter<'w, DrawRequestEvent>,
+    draw: MessageWriter<'w, DrawRequestEvent>,
-    forfeit: EventWriter<'w, ForfeitEvent>,
+    forfeit: MessageWriter<'w, ForfeitEvent>,
-    hint_visual: EventWriter<'w, HintVisualEvent>,
+    hint_visual: MessageWriter<'w, HintVisualEvent>,
 }
 #[allow(clippy::too_many_arguments)]
@@ -308,8 +308,8 @@ fn handle_keyboard(
 /// game plugin fires after dealing — preventing a stale hint from the previous
 /// game being shown when H is pressed in that gap frame.
 fn reset_hint_cycle_on_state_change(
-    mut state_events: EventReader<StateChangedEvent>,
+    mut state_events: MessageReader<StateChangedEvent>,
-    mut new_game_events: EventReader<NewGameRequestEvent>,
+    mut new_game_events: MessageReader<NewGameRequestEvent>,
    mut hint_cycle: ResMut<HintCycleIndex>,
 ) {
    if state_events.read().next().is_some() || new_game_events.read().next().is_some() {
@@ -322,7 +322,7 @@ fn reset_hint_cycle_on_state_change(
 fn handle_fullscreen(
    keys: Res<ButtonInput<KeyCode>>,
    mut windows: Query<&mut Window, With<PrimaryWindow>>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    if !keys.just_pressed(KeyCode::F11) {
        return;
@@ -347,7 +347,7 @@ fn handle_stock_click(
    windows: Query<&Window, With<PrimaryWindow>>,
    cameras: Query<(&Camera, &GlobalTransform)>,
    layout: Option<Res<LayoutResource>>,
-    mut draw: EventWriter<DrawRequestEvent>,
+    mut draw: MessageWriter<DrawRequestEvent>,
 ) {
    if paused.is_some_and(|p| p.0) {
        return;
@@ -467,9 +467,9 @@ fn end_drag(
    layout: Option<Res<LayoutResource>>,
    game: Res<GameStateResource>,
    mut drag: ResMut<DragState>,
-    mut moves: EventWriter<MoveRequestEvent>,
+    mut moves: MessageWriter<MoveRequestEvent>,
-    mut rejected: EventWriter<MoveRejectedEvent>,
+    mut rejected: MessageWriter<MoveRejectedEvent>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
    mut commands: Commands,
    card_entities: Query<(Entity, &CardEntity, &Transform)>,
 ) {
@@ -809,8 +809,8 @@ fn handle_double_click(
    layout: Option<Res<LayoutResource>>,
    game: Res<GameStateResource>,
    mut last_click: Local<HashMap<u32, f32>>,
-    mut moves: EventWriter<MoveRequestEvent>,
+    mut moves: MessageWriter<MoveRequestEvent>,
-    mut rejected: EventWriter<MoveRejectedEvent>,
+    mut rejected: MessageWriter<MoveRejectedEvent>,
 ) {
    if paused.is_some_and(|p| p.0) {
        return;
@@ -218,7 +218,7 @@ fn handle_opt_in_button(
 /// Polls the opt-in task; fires an `InfoToastEvent` on completion or failure.
 fn poll_opt_in_task(
    mut task_res: ResMut<OptInTask>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    let Some(task) = task_res.0.as_mut() else { return };
    let Some(result) = future::block_on(future::poll_once(task)) else { return };
@@ -258,7 +258,7 @@ fn handle_opt_out_button(
 /// Polls the opt-out task; fires an `InfoToastEvent` on completion or failure.
 fn poll_opt_out_task(
    mut task_res: ResMut<OptOutTask>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    let Some(task) = task_res.0.as_mut() else { return };
    let Some(result) = future::block_on(future::poll_once(task)) else { return };
@@ -54,8 +54,8 @@ impl Plugin for PausePlugin {
    fn build(&self, app: &mut App) {
        // Both add_event calls are idempotent — other plugins may register these
        // events first, but calling add_event again is always safe.
-        app.add_event::<SettingsChangedEvent>()
+        app.add_message::<SettingsChangedEvent>()
-            .add_event::<StateChangedEvent>()
+            .add_message::<StateChangedEvent>()
            .init_resource::<PausedResource>()
            .add_systems(Update, (toggle_pause, handle_pause_draw_toggle));
    }
@@ -74,7 +74,7 @@ fn toggle_pause(
    stats: Option<Res<StatsResource>>,
    settings: Option<Res<SettingsResource>>,
    mut drag: Option<ResMut<DragState>>,
-    mut changed: EventWriter<StateChangedEvent>,
+    mut changed: MessageWriter<StateChangedEvent>,
 ) {
    if !keys.just_pressed(KeyCode::Escape) {
        return;
@@ -125,7 +125,7 @@ fn handle_pause_draw_toggle(
    paused: Res<PausedResource>,
    settings: Option<ResMut<SettingsResource>>,
    path: Option<Res<SettingsStoragePath>>,
-    mut changed: EventWriter<SettingsChangedEvent>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
 ) {
    if !paused.0 {
        return;
@@ -25,7 +25,7 @@ pub struct ProgressResource(pub PlayerProgress);
 pub struct ProgressStoragePath(pub Option<PathBuf>);
 /// Fired when a win pushes the player to a new level.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct LevelUpEvent {
    pub previous_level: u32,
    pub new_level: u32,
@@ -64,9 +64,9 @@ impl Plugin for ProgressPlugin {
        };
        app.insert_resource(ProgressResource(loaded))
            .insert_resource(ProgressStoragePath(self.storage_path.clone()))
-            .add_event::<LevelUpEvent>()
+            .add_message::<LevelUpEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
            .add_systems(
                Update,
                award_xp_on_win
@@ -77,9 +77,9 @@ impl Plugin for ProgressPlugin {
 }
 fn award_xp_on_win(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
-    mut levelups: EventWriter<LevelUpEvent>,
+    mut levelups: MessageWriter<LevelUpEvent>,
-    mut xp_awarded: EventWriter<XpAwardedEvent>,
+    mut xp_awarded: MessageWriter<XpAwardedEvent>,
    game: Res<GameStateResource>,
    path: Res<ProgressStoragePath>,
    mut progress: ResMut<ProgressResource>,
@@ -131,7 +131,7 @@ mod tests {
    fn win_awards_base_xp() {
        let mut app = headless_app();
        // Game starts with undo_count = 0, so the no-undo bonus applies.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300, // no speed bonus
        });
@@ -150,7 +150,7 @@ mod tests {
            .0
            .undo_count = 1;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300,
        });
@@ -164,7 +164,7 @@ mod tests {
    #[test]
    fn fast_win_includes_speed_bonus() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 0,
        });
@@ -181,7 +181,7 @@ mod tests {
        // Pre-load 480 XP so a 75-XP win pushes us over the 500 boundary.
        app.world_mut().resource_mut::<ProgressResource>().0.total_xp = 480;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300,
        });
@@ -198,7 +198,7 @@ mod tests {
    #[test]
    fn win_without_level_change_does_not_fire_levelup() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300,
        });
@@ -213,7 +213,7 @@ mod tests {
    fn xp_awarded_event_fired_with_correct_amount() {
        let mut app = headless_app();
        // Slow win, no undo → base 50 + no_undo 25 = 75
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300,
        });
@@ -231,7 +231,7 @@ mod tests {
        let mut app = headless_app();
        app.world_mut().resource_mut::<ProgressResource>().0.total_xp = 480;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 300,
        });
@@ -256,7 +256,7 @@ mod tests {
            .0
            .mode = solitaire_core::game_state::GameMode::Zen;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 0,        // Zen mode keeps score at 0
            time_seconds: 300,
        });
@@ -162,8 +162,8 @@ fn handle_selection_keys(
    paused: Option<Res<PausedResource>>,
    game: Res<GameStateResource>,
    mut selection: ResMut<SelectionState>,
-    mut moves: EventWriter<MoveRequestEvent>,
+    mut moves: MessageWriter<MoveRequestEvent>,
-    mut info_toast: EventWriter<InfoToastEvent>,
+    mut info_toast: MessageWriter<InfoToastEvent>,
 ) {
    if paused.is_some_and(|p| p.0) {
        return;
@@ -36,7 +36,7 @@ pub struct SettingsStoragePath(pub Option<PathBuf>);
 pub struct SettingsScreen(pub bool);
 /// Fired whenever settings change so consumers (audio, UI) can react.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct SettingsChangedEvent(pub Settings);
 /// Marker on the root Settings panel entity.
@@ -144,9 +144,9 @@ impl Plugin for SettingsPlugin {
            .insert_resource(SettingsStoragePath(self.storage_path.clone()))
            .init_resource::<SettingsScreen>()
            .init_resource::<SettingsScrollPos>()
-            .add_event::<SettingsChangedEvent>()
+            .add_message::<SettingsChangedEvent>()
-            .add_event::<ManualSyncRequestEvent>()
+            .add_message::<ManualSyncRequestEvent>()
-            .add_event::<bevy::input::mouse::MouseWheel>()
+            .add_message::<bevy::input::mouse::MouseWheel>()
            .add_systems(Update, (handle_volume_keys, toggle_settings_screen, scroll_settings_panel));
        if self.ui_enabled {
@@ -185,7 +185,7 @@ fn handle_volume_keys(
    keys: Res<ButtonInput<KeyCode>>,
    mut settings: ResMut<SettingsResource>,
    path: Res<SettingsStoragePath>,
-    mut changed: EventWriter<SettingsChangedEvent>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
 ) {
    let mut delta = 0.0_f32;
    if keys.just_pressed(KeyCode::BracketLeft) {
@@ -257,7 +257,7 @@ fn sync_settings_panel_visibility(
    } else {
        // Save the current scroll offset before despawning the panel.
        if let Ok(sp) = scroll_nodes.single() {
-            scroll_pos.0 = sp.offset_y;
+            scroll_pos.0 = sp.0.y;
        }
        for entity in &panels {
            commands.entity(entity).despawn();
@@ -383,8 +383,8 @@ fn handle_settings_buttons(
    mut settings: ResMut<SettingsResource>,
    mut screen: ResMut<SettingsScreen>,
    path: Res<SettingsStoragePath>,
-    mut changed: EventWriter<SettingsChangedEvent>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
-    mut manual_sync: EventWriter<ManualSyncRequestEvent>,
+    mut manual_sync: MessageWriter<ManualSyncRequestEvent>,
    mut sfx_text: Query<&mut Text, (With<SfxVolumeText>, Without<MusicVolumeText>, Without<DrawModeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>)>,
    mut music_text: Query<&mut Text, (With<MusicVolumeText>, Without<SfxVolumeText>, Without<DrawModeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>)>,
    mut draw_text: Query<&mut Text, (With<DrawModeText>, Without<SfxVolumeText>, Without<MusicVolumeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>)>,
@@ -537,7 +537,7 @@ fn color_blind_label(enabled: bool) -> String {
 /// adds to the offset; scrolling up subtracts. Clamped to >= 0 so it never
 /// scrolls past the top.
 fn scroll_settings_panel(
-    mut scroll_evr: EventReader<MouseWheel>,
+    mut scroll_evr: MessageReader<MouseWheel>,
    screen: Res<SettingsScreen>,
    mut scrollables: Query<&mut ScrollPosition, With<SettingsPanelScrollable>>,
 ) {
@@ -556,7 +556,7 @@ fn scroll_settings_panel(
        return;
    }
    for mut sp in scrollables.iter_mut() {
-        sp.offset_y = (sp.offset_y - delta_y).max(0.0);
+        sp.0.y = (sp.0.y - delta_y).max(0.0);
    }
 }
@@ -595,7 +595,7 @@ fn spawn_settings_panel(
            root.spawn((
                SettingsPanelScrollable,
                SettingsScrollNode,
-                ScrollPosition { offset_y: scroll_offset, ..default() },
+                ScrollPosition(Vec2::new(0.0, scroll_offset)),
                Node {
                    flex_direction: FlexDirection::Column,
                    padding: UiRect::all(Val::Px(28.0)),
@@ -1095,7 +1095,7 @@ mod tests {
            .spawn((SettingsPanelScrollable, ScrollPosition::default()))
            .id();
        // Send a downward scroll event while the panel is closed.
-        app.world_mut().send_event(MouseWheel {
+        app.world_mut().write_message(MouseWheel {
            unit: MouseScrollUnit::Line,
            x: 0.0,
            y: -3.0,
@@ -1108,7 +1108,7 @@ mod tests {
            .entity(entity)
            .get::<ScrollPosition>()
            .unwrap()
-            .offset_y;
+            .0.y;
        assert_eq!(offset, 0.0, "scroll must not move when panel is closed");
    }
@@ -1123,11 +1123,11 @@ mod tests {
            .world_mut()
            .spawn((
                SettingsPanelScrollable,
-                ScrollPosition { offset_y: 100.0, ..default() },
+                ScrollPosition(Vec2::new(0.0, 100.0)),
            ))
            .id();
        // Scroll down by 2 lines (50 px/line → +100 px added to offset_y).
-        app.world_mut().send_event(MouseWheel {
+        app.world_mut().write_message(MouseWheel {
            unit: MouseScrollUnit::Line,
            x: 0.0,
            y: -2.0,
@@ -1139,7 +1139,7 @@ mod tests {
            .entity(entity)
            .get::<ScrollPosition>()
            .unwrap()
-            .offset_y;
+            .0.y;
        assert!((offset - 200.0).abs() < 1e-3, "scrolling down should increase offset_y; got {offset}");
    }
@@ -1153,11 +1153,11 @@ mod tests {
            .world_mut()
            .spawn((
                SettingsPanelScrollable,
-                ScrollPosition { offset_y: 10.0, ..default() },
+                ScrollPosition(Vec2::new(0.0, 10.0)),
            ))
            .id();
        // Scroll up by 5 lines → would subtract 250 px, but must clamp to 0.
-        app.world_mut().send_event(MouseWheel {
+        app.world_mut().write_message(MouseWheel {
            unit: MouseScrollUnit::Line,
            x: 0.0,
            y: 5.0,
@@ -1169,7 +1169,7 @@ mod tests {
            .entity(entity)
            .get::<ScrollPosition>()
            .unwrap()
-            .offset_y;
+            .0.y;
        assert_eq!(offset, 0.0, "scrolling past top must clamp to 0, got {offset}");
    }
 }
@@ -77,10 +77,10 @@ impl Plugin for StatsPlugin {
        };
        app.insert_resource(StatsResource(loaded))
            .insert_resource(StatsStoragePath(self.storage_path.clone()))
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<ForfeitEvent>()
+            .add_message::<ForfeitEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
            // record_abandoned must read `move_count` BEFORE handle_new_game
            // clobbers it with a fresh game.
            .add_systems(
@@ -111,7 +111,7 @@ fn persist(path: &StatsStoragePath, stats: &StatsSnapshot, context: &str) {
 }
 fn update_stats_on_win(
-    mut events: EventReader<GameWonEvent>,
+    mut events: MessageReader<GameWonEvent>,
    game: Res<GameStateResource>,
    mut stats: ResMut<StatsResource>,
    path: Res<StatsStoragePath>,
@@ -125,11 +125,11 @@ fn update_stats_on_win(
 }
 fn update_stats_on_new_game(
-    mut events: EventReader<NewGameRequestEvent>,
+    mut events: MessageReader<NewGameRequestEvent>,
    game: Res<GameStateResource>,
    mut stats: ResMut<StatsResource>,
    path: Res<StatsStoragePath>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    for _ in events.read() {
        if game.0.move_count > 0 && !game.0.is_won {
@@ -149,12 +149,12 @@ fn update_stats_on_new_game(
 /// `AutoCompleteState` is reset here so the "AUTO" badge and chime do not bleed
 /// into the new deal (task #41).
 fn handle_forfeit(
-    mut events: EventReader<ForfeitEvent>,
+    mut events: MessageReader<ForfeitEvent>,
    game: Res<GameStateResource>,
    mut stats: ResMut<StatsResource>,
    path: Res<StatsStoragePath>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
    mut auto_complete: Option<ResMut<AutoCompleteState>>,
 ) {
    for _ in events.read() {
@@ -513,7 +513,7 @@ mod tests {
    #[test]
    fn win_event_increments_games_won() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 1000,
            time_seconds: 120,
        });
@@ -532,7 +532,7 @@ mod tests {
            .0
            .draw_mode = solitaire_core::game_state::DrawMode::DrawThree;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -553,7 +553,7 @@ mod tests {
            .move_count = 3;
        app.world_mut()
-            .send_event(NewGameRequestEvent { seed: Some(999), mode: None });
+            .write_message(NewGameRequestEvent { seed: Some(999), mode: None });
        app.update();
        let stats = &app.world().resource::<StatsResource>().0;
@@ -566,7 +566,7 @@ mod tests {
    fn new_game_without_moves_does_not_record_abandoned() {
        let mut app = headless_app();
        app.world_mut()
-            .send_event(NewGameRequestEvent { seed: Some(42), mode: None });
+            .write_message(NewGameRequestEvent { seed: Some(42), mode: None });
        app.update();
        let stats = &app.world().resource::<StatsResource>().0;
@@ -781,7 +781,7 @@ mod tests {
            .0
            .move_count = 1;
-        app.world_mut().send_event(ForfeitEvent);
+        app.world_mut().write_message(ForfeitEvent);
        app.update();
        let events = app.world().resource::<Events<InfoToastEvent>>();
@@ -810,7 +810,7 @@ mod tests {
            .0
            .move_count = 1;
-        app.world_mut().send_event(ForfeitEvent);
+        app.world_mut().write_message(ForfeitEvent);
        app.update();
        let events = app.world().resource::<Events<InfoToastEvent>>();
@@ -93,7 +93,7 @@ impl Plugin for SyncPlugin {
            .init_resource::<SyncStatusResource>()
            .init_resource::<PullTaskResult>()
            .init_resource::<PullTask>()
-            .add_event::<ManualSyncRequestEvent>()
+            .add_message::<ManualSyncRequestEvent>()
            .add_systems(Startup, start_pull)
            .add_systems(Update, (poll_pull_result, handle_manual_sync_request))
            .add_systems(Last, push_on_exit);
@@ -121,7 +121,7 @@ fn start_pull(
 /// Update system: starts a new pull task when `ManualSyncRequestEvent` is
 /// received, but only if no pull is already in flight.
 fn handle_manual_sync_request(
-    mut events: EventReader<ManualSyncRequestEvent>,
+    mut events: MessageReader<ManualSyncRequestEvent>,
    provider: Res<SyncProviderResource>,
    mut task_res: ResMut<PullTask>,
    mut status: ResMut<SyncStatusResource>,
@@ -217,7 +217,7 @@ fn poll_pull_result(
 /// that blocking on exit is permitted because the game loop is already
 /// shutting down.
 fn push_on_exit(
-    mut exit_events: EventReader<AppExit>,
+    mut exit_events: MessageReader<AppExit>,
    provider: Res<SyncProviderResource>,
    stats: Res<StatsResource>,
    achievements: Res<AchievementsResource>,
@@ -47,9 +47,9 @@ impl Plugin for TablePlugin {
        // Register WindowResized so the plugin works under MinimalPlugins in
        // tests. Under DefaultPlugins, bevy_window has already registered it
        // and this call is a no-op.
-        app.add_event::<WindowResized>()
+        app.add_message::<WindowResized>()
-            .add_event::<SettingsChangedEvent>()
+            .add_message::<SettingsChangedEvent>()
-            .add_event::<HintVisualEvent>()
+            .add_message::<HintVisualEvent>()
            .add_systems(Startup, setup_table)
            .add_systems(
                Update,
@@ -133,7 +133,7 @@ fn spawn_background(commands: &mut Commands, window_size: Vec2, color: Color) {
 }
 fn apply_theme_on_settings_change(
-    mut events: EventReader<SettingsChangedEvent>,
+    mut events: MessageReader<SettingsChangedEvent>,
    mut backgrounds: Query<&mut Sprite, With<TableBackground>>,
 ) {
    let Some(ev) = events.read().last() else {
@@ -213,7 +213,7 @@ fn spawn_pile_markers(commands: &mut Commands, layout: &Layout) {
 #[allow(clippy::type_complexity)]
 fn on_window_resized(
-    mut events: EventReader<WindowResized>,
+    mut events: MessageReader<WindowResized>,
    mut layout_res: Option<ResMut<LayoutResource>>,
    mut backgrounds: Query<
        (&mut Sprite, &mut Transform),
@@ -261,7 +261,7 @@ const HINT_PILE_HIGHLIGHT_COLOUR: Color = Color::srgb(1.0, 0.85, 0.1);
 /// If the pile marker already has a `HintPileHighlight` from a previous hint
 /// press, the timer is reset to 2 s without changing `original_color`.
 fn apply_hint_pile_highlight(
-    mut events: EventReader<HintVisualEvent>,
+    mut events: MessageReader<HintVisualEvent>,
    mut commands: Commands,
    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite, Option<&HintPileHighlight>)>,
 ) {
@@ -26,7 +26,7 @@ pub struct TimeAttackResource {
 /// Fired when the Time Attack timer expires. The summary toast in
 /// `AnimationPlugin` consumes this; UI/stats consumers can also subscribe.
-#[derive(Event, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone, Copy)]
 pub struct TimeAttackEndedEvent {
    pub wins: u32,
 }
@@ -36,10 +36,10 @@ pub struct TimeAttackPlugin;
 impl Plugin for TimeAttackPlugin {
    fn build(&self, app: &mut App) {
        app.init_resource::<TimeAttackResource>()
-            .add_event::<TimeAttackEndedEvent>()
+            .add_message::<TimeAttackEndedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
            .add_systems(
                Update,
                handle_start_time_attack_request.before(GameMutation),
@@ -53,8 +53,8 @@ fn handle_start_time_attack_request(
    keys: Res<ButtonInput<KeyCode>>,
    progress: Res<ProgressResource>,
    mut session: ResMut<TimeAttackResource>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
-    mut info_toast: EventWriter<InfoToastEvent>,
+    mut info_toast: MessageWriter<InfoToastEvent>,
 ) {
    if !keys.just_pressed(KeyCode::KeyT) {
        return;
@@ -79,7 +79,7 @@ fn handle_start_time_attack_request(
 fn advance_time_attack(
    time: Res<Time>,
    mut session: ResMut<TimeAttackResource>,
-    mut ended: EventWriter<TimeAttackEndedEvent>,
+    mut ended: MessageWriter<TimeAttackEndedEvent>,
    paused: Option<Res<crate::pause_plugin::PausedResource>>,
 ) {
    if !session.active {
@@ -98,10 +98,10 @@ fn advance_time_attack(
 }
 fn auto_deal_on_time_attack_win(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
    game: Res<GameStateResource>,
    mut session: ResMut<TimeAttackResource>,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
 ) {
    for _ in wins.read() {
        if !session.active || game.0.mode != GameMode::TimeAttack {
@@ -213,7 +213,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::TimeAttack);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -237,7 +237,7 @@ mod tests {
        app.world_mut().resource_mut::<GameStateResource>().0 =
            GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::TimeAttack);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -256,7 +256,7 @@ mod tests {
            wins: 0,
        };
        // GameStateResource defaults to Classic mode.
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -15,7 +15,7 @@ use crate::progress_plugin::{LevelUpEvent, ProgressResource, ProgressStoragePath
 use crate::resources::GameStateResource;
 /// Fired when the player has just completed a weekly goal.
-#[derive(Event, Debug, Clone)]
+#[derive(Message, Debug, Clone)]
 pub struct WeeklyGoalCompletedEvent {
    pub goal_id: String,
    pub description: String,
@@ -25,9 +25,9 @@ pub struct WeeklyGoalsPlugin;
 impl Plugin for WeeklyGoalsPlugin {
    fn build(&self, app: &mut App) {
-        app.add_event::<WeeklyGoalCompletedEvent>()
+        app.add_message::<WeeklyGoalCompletedEvent>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
            .add_systems(Startup, roll_weekly_goals_on_startup)
            // Run after GameMutation (so GameWonEvent is available) and
            // ProgressUpdate (so we don't fight ProgressPlugin's add_xp).
@@ -57,13 +57,13 @@ fn roll_weekly_goals_on_startup(
 }
 fn evaluate_weekly_goals(
-    mut wins: EventReader<GameWonEvent>,
+    mut wins: MessageReader<GameWonEvent>,
    game: Res<GameStateResource>,
    mut progress: ResMut<ProgressResource>,
    path: Res<ProgressStoragePath>,
-    mut completions: EventWriter<WeeklyGoalCompletedEvent>,
+    mut completions: MessageWriter<WeeklyGoalCompletedEvent>,
-    mut levelups: EventWriter<LevelUpEvent>,
+    mut levelups: MessageWriter<LevelUpEvent>,
-    mut xp_awarded: EventWriter<XpAwardedEvent>,
+    mut xp_awarded: MessageWriter<XpAwardedEvent>,
 ) {
    let mut events: Vec<&GameWonEvent> = wins.read().collect();
    if events.is_empty() {
@@ -149,7 +149,7 @@ mod tests {
    #[test]
    fn first_win_increments_win_game_goal() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -164,7 +164,7 @@ mod tests {
    #[test]
    fn fast_win_ticks_fast_goal_too() {
        let mut app = headless_app();
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -181,7 +181,7 @@ mod tests {
            .0
            .undo_count = 1;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 200,
        });
@@ -214,7 +214,7 @@ mod tests {
        let xp_before = app.world().resource::<ProgressResource>().0.total_xp;
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -280,7 +280,7 @@ mod tests {
            .0
            .weekly_goal_week_iso = Some(key);
-        app.world_mut().send_event(GameWonEvent {
+        app.world_mut().write_message(GameWonEvent {
            score: 500,
            time_seconds: 60,
        });
@@ -159,11 +159,11 @@ impl Plugin for WinSummaryPlugin {
        app.init_resource::<WinSummaryPending>()
            .init_resource::<ScreenShakeResource>()
            .init_resource::<SessionAchievements>()
-            .add_event::<GameWonEvent>()
+            .add_message::<GameWonEvent>()
-            .add_event::<XpAwardedEvent>()
+            .add_message::<XpAwardedEvent>()
-            .add_event::<NewGameRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
-            .add_event::<InfoToastEvent>()
+            .add_message::<InfoToastEvent>()
-            .add_event::<AchievementUnlockedEvent>()
+            .add_message::<AchievementUnlockedEvent>()
            // `cache_win_data` must run BEFORE `StatsUpdate` so it can compare
            // the player's old personal-best values before `StatsPlugin` overwrites them.
            .add_systems(
@@ -221,13 +221,13 @@ pub fn format_win_time(seconds: u64) -> String {
 /// This system is scheduled `.before(StatsUpdate)` so the comparison always
 /// sees the old best values.
 fn cache_win_data(
-    mut won: EventReader<GameWonEvent>,
+    mut won: MessageReader<GameWonEvent>,
-    mut xp: EventReader<XpAwardedEvent>,
+    mut xp: MessageReader<XpAwardedEvent>,
    mut pending: ResMut<WinSummaryPending>,
    stats: Res<StatsResource>,
    game: Res<GameStateResource>,
    progress: Res<ProgressResource>,
-    mut toast: EventWriter<InfoToastEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
    for ev in won.read() {
        // Compare against old personal bests BEFORE StatsPlugin updates them.
@@ -274,8 +274,8 @@ fn cache_win_data(
 /// reader covers every implicit game-context reset in addition to the
 /// explicit N / "Play Again" new-game requests.
 fn collect_session_achievements(
-    mut unlocks: EventReader<AchievementUnlockedEvent>,
+    mut unlocks: MessageReader<AchievementUnlockedEvent>,
-    mut new_games: EventReader<NewGameRequestEvent>,
+    mut new_games: MessageReader<NewGameRequestEvent>,
    mut session: ResMut<SessionAchievements>,
 ) {
    // Reset on any new-game request (including mode switches via Z/X/C/T) so
@@ -303,8 +303,8 @@ fn collect_session_achievements(
 #[allow(clippy::too_many_arguments)]
 fn spawn_win_summary_after_delay(
    mut commands: Commands,
-    mut won: EventReader<GameWonEvent>,
+    mut won: MessageReader<GameWonEvent>,
-    mut xp_events: EventReader<XpAwardedEvent>,
+    mut xp_events: MessageReader<XpAwardedEvent>,
    mut shake: ResMut<ScreenShakeResource>,
    mut pending: ResMut<WinSummaryPending>,
    session: Res<SessionAchievements>,
@@ -352,7 +352,7 @@ fn handle_win_summary_buttons(
    interaction_query: Query<(&Interaction, &WinSummaryButton), Changed<Interaction>>,
    overlays: Query<Entity, With<WinSummaryOverlay>>,
    mut commands: Commands,
-    mut new_game: EventWriter<NewGameRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
 ) {
    for (interaction, button) in &interaction_query {
        if *interaction != Interaction::Pressed {
@@ -677,7 +677,7 @@ mod tests {
        use solitaire_data::AchievementRecord;
        let record = AchievementRecord::locked("first_win");
        app.world_mut()
-            .send_event(AchievementUnlockedEvent(record));
+            .write_message(AchievementUnlockedEvent(record));
        app.update();
        let session = app.world().resource::<SessionAchievements>();
@@ -693,7 +693,7 @@ mod tests {
        use solitaire_data::AchievementRecord;
        let record = AchievementRecord::locked("first_win");
        app.world_mut()
-            .send_event(AchievementUnlockedEvent(record));
+            .write_message(AchievementUnlockedEvent(record));
        app.update();
        // Confirm it was recorded.
@@ -703,7 +703,7 @@ mod tests {
        );
        // Fire NewGameRequestEvent — should clear the list.
-        app.world_mut().send_event(NewGameRequestEvent::default());
+        app.world_mut().write_message(NewGameRequestEvent::default());
        app.update();
        assert!(
@@ -727,7 +727,7 @@ mod tests {
        // Simulate an achievement unlock during the current session.
        let record = AchievementRecord::locked("first_win");
        app.world_mut()
-            .send_event(AchievementUnlockedEvent(record));
+            .write_message(AchievementUnlockedEvent(record));
        app.update();
        assert_eq!(
@@ -739,7 +739,7 @@ mod tests {
        // Simulate pressing Z (Zen mode switch) — fires NewGameRequestEvent
        // with mode = Some(Zen). Same event shape used by X (Challenge),
        // C (Daily Challenge), and T (Time Attack).
-        app.world_mut().send_event(NewGameRequestEvent {
+        app.world_mut().write_message(NewGameRequestEvent {
            seed: None,
            mode: Some(GameMode::Zen),
        });
@@ -756,7 +756,7 @@ mod tests {
        let mut app = make_app();
        app.world_mut()
-            .send_event(GameWonEvent { score: 1234, time_seconds: 90 });
+            .write_message(GameWonEvent { score: 1234, time_seconds: 90 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -771,8 +771,8 @@ mod tests {
    fn cache_win_data_sets_xp_from_xp_awarded_event() {
        let mut app = make_app();
-        app.world_mut().send_event(GameWonEvent { score: 0, time_seconds: 0 });
+        app.world_mut().write_message(GameWonEvent { score: 0, time_seconds: 0 });
-        app.world_mut().send_event(XpAwardedEvent { amount: 75 });
+        app.world_mut().write_message(XpAwardedEvent { amount: 75 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -784,7 +784,7 @@ mod tests {
        let mut app = make_app();
        app.world_mut()
-            .send_event(GameWonEvent { score: 0, time_seconds: 0 });
+            .write_message(GameWonEvent { score: 0, time_seconds: 0 });
        app.update();
        let shake = app.world().resource::<ScreenShakeResource>();
@@ -802,7 +802,7 @@ mod tests {
        let mut app = make_app();
        app.world_mut()
-            .send_event(GameWonEvent { score: 500, time_seconds: 120 });
+            .write_message(GameWonEvent { score: 500, time_seconds: 120 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -820,7 +820,7 @@ mod tests {
        // Score 500 beats previous best of 400.
        app.world_mut()
-            .send_event(GameWonEvent { score: 500, time_seconds: 300 });
+            .write_message(GameWonEvent { score: 500, time_seconds: 300 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -838,7 +838,7 @@ mod tests {
        // Score 500 does not beat 800, but time 100 < 200.
        app.world_mut()
-            .send_event(GameWonEvent { score: 500, time_seconds: 100 });
+            .write_message(GameWonEvent { score: 500, time_seconds: 100 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -856,7 +856,7 @@ mod tests {
        // Score 500 < 800 and time 120 > 60 — neither record broken.
        app.world_mut()
-            .send_event(GameWonEvent { score: 500, time_seconds: 120 });
+            .write_message(GameWonEvent { score: 500, time_seconds: 120 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -887,7 +887,7 @@ mod tests {
        }
        app.world_mut()
-            .send_event(GameWonEvent { score: 0, time_seconds: 0 });
+            .write_message(GameWonEvent { score: 0, time_seconds: 0 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();
@@ -903,7 +903,7 @@ mod tests {
        let mut app = make_app();
        // Default game mode is Classic — challenge_level should stay None.
        app.world_mut()
-            .send_event(GameWonEvent { score: 0, time_seconds: 0 });
+            .write_message(GameWonEvent { score: 0, time_seconds: 0 });
        app.update();
        let pending = app.world().resource::<WinSummaryPending>();