Merge pull request 'docs(changelog): cut v0.42.0 section' (#151) from docs/changelog-v0.42.0 into master

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -6,6 +6,47 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+## [0.42.0] — 2026-07-06
+
+### Added
+
+- **CI workspace gate.** New `test.yml` workflow runs clippy (deny warnings)
+  and the full test suite on every master push and PR — previously no CI ran
+  tests at all. Caught its own first bug (missing Bevy native deps) on its
+  own PR. (#135)
+- **Schedule ambiguity gate.** A headless test builds the gameplay plugin
+  cluster with Bevy ambiguity detection promoted to error. The initial
+  measurement found 302 system pairs with conflicting data access and no
+  ordering; four burn-down batches (PRs #146–#149) took it to ZERO the same
+  day, and the gate now enforces 0. Keyboard consumption, board painting,
+  and HUD updates all have deterministic order for the first time.
+
+### Changed
+
+- **Browser canvas 36% smaller.** `canvas_bg.wasm` shrank 36.2 MB → 23.2 MB
+  via a size-focused `wasm-release` profile (fat LTO, single codegen unit,
+  opt-level "s"); verified visually identical in production. (#134)
+- **Quaternions API adoption.** Canonical `FOUNDATIONS`/`TABLEAUS` consts in
+  `solitaire_core` replace five scattered enum lists; upstream
+  `Suit::SUITS`/`Rank::RANKS` replace nine hand-rolled arrays, with the
+  texture-atlas indexing re-keyed through tested canonical helpers. Net
+  −177 lines. (#137)
+
+### Fixed
+
+- **Sync push race.** The server's load→merge→store cycle now runs in one
+  transaction; concurrent pushes from two devices can no longer overwrite
+  each other's merge. (#136)
+- **Refresh-token rotation is single-use under concurrency** — rotation
+  gates on the DELETE's row count, so a stolen-then-replayed refresh token
+  loses the race and gets 401. (#136)
+- **Exit sync push actually completes.** Was a detached task killed by
+  process teardown; now a bounded 2-second blocking wait on the app's final
+  frame. (#138)
+- **Server auth hardening.** Login timing no longer reveals whether a
+  username exists; concurrent duplicate registration returns 409 instead of
+  500; avatar uploads are magic-byte checked. (#144, issues #139–#141)
+
 ## [0.41.1] — 2026-07-06
 
 ### Fixed

solitaire_engine/src/auto_complete_plugin.rs

@@ -46,6 +46,11 @@ pub struct AutoCompleteState {
 /// Plugin that drives the auto-complete sequence.
 pub struct AutoCompletePlugin;
 
+/// Set wrapping the auto-complete detect/drive chain; HUD readers of
+/// [`AutoCompleteState`] order themselves after it (#143).
+#[derive(bevy::ecs::schedule::SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct AutoComplete;
+
 impl Plugin for AutoCompletePlugin {
     fn build(&self, app: &mut App) {
         app.init_resource::<AutoCompleteState>()
@@ -58,7 +63,9 @@ impl Plugin for AutoCompletePlugin {
                     drive_auto_complete,
                 )
                     .chain()
-                    .after(GameMutation),
+                    .in_set(AutoComplete)
+                    .after(GameMutation)
+                    .before(crate::card_plugin::BoardVisuals),
             );
     }
 }

solitaire_engine/src/card_plugin/mod.rs

@@ -533,6 +533,17 @@ fn should_apply_resize(now_secs: f32, last_applied_secs: f32) -> bool {
 /// Renders cards by reading `GameStateResource` on `StateChangedEvent`.
 pub struct CardPlugin;
 
+/// System set for everything that paints the board: card sprites, pile
+/// markers, shadows, highlights, badges. Members mutate `Sprite` /
+/// `Transform` on board entities and run as a deterministic chain (see the
+/// registration in [`CardPlugin`]'s `build`); table-plugin marker painters
+/// order themselves after this set. UI-domain systems that touch `Sprite`/
+/// `Transform` on non-board entities (HUD text pulses, modal cards) declare
+/// `.ambiguous_with(BoardVisuals)` instead — the entity domains are
+/// disjoint by design (#143).
+#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct BoardVisuals;
+
 impl Plugin for CardPlugin {
     fn build(&self, app: &mut App) {
         // PostStartup ensures TablePlugin's Startup system has inserted
@@ -558,35 +569,45 @@ impl Plugin for CardPlugin {
                     update_stock_empty_indicator_startup,
                 ),
             )
+            // Layout recompute (UpdateOnResize) always precedes board
+            // painting, and the painters run as ONE deterministic chain in
+            // data-flow order: layout refinement → card authority → anims →
+            // shadows → highlights → indicators → resize snapping → labels.
+            // Every painter mutates card/marker Sprite+Transform, so without
+            // the chain each pair is a scheduler ambiguity (#143). All
+            // members are cheap and mostly change-gated; sequential
+            // execution is not a cost that matters here.
+            .configure_sets(
+                Update,
+                LayoutSystem::UpdateOnResize.before(BoardVisuals),
+            )
             .add_systems(
                 Update,
                 (
-                    update_tableau_fan_frac
-                        .after(GameMutation)
-                        .before(sync_cards_on_change),
-                    sync_cards_on_change.after(GameMutation),
-                    resync_cards_on_settings_change.before(sync_cards_on_change),
-                    start_flip_anim.after(GameMutation),
+                    update_tableau_fan_frac,
+                    resync_cards_on_settings_change,
+                    sync_cards_on_change,
+                    start_flip_anim,
                     tick_flip_anim,
                     update_drag_shadow,
-                    update_card_shadows_on_drag.after(sync_cards_on_change),
-                    tick_hint_highlight.after(GameMutation),
-                    handle_right_click.after(GameMutation),
+                    update_card_shadows_on_drag,
+                    handle_right_click,
                     tick_right_click_highlights,
-                    clear_right_click_highlights_on_state_change.after(GameMutation),
+                    clear_right_click_highlights_on_state_change,
                     clear_right_click_highlights_on_pause,
-                    update_stock_empty_indicator.after(GameMutation),
+                    tick_hint_highlight,
+                    update_stock_empty_indicator,
                     update_stock_count_badge
-                        .after(GameMutation)
                         .run_if(resource_changed::<GameStateResource>),
-                    collect_resize_events.after(LayoutSystem::UpdateOnResize),
-                    snap_cards_on_window_resize
-                        .after(collect_resize_events)
-                        .after(GameMutation),
-                ),
+                    collect_resize_events,
+                    snap_cards_on_window_resize,
+                    resize_android_corner_labels,
+                )
+                    .chain()
+                    .in_set(BoardVisuals)
+                    .after(GameMutation),
             );
 
-        app.add_systems(Update, resize_android_corner_labels);
         app.add_systems(PostUpdate, rebuild_card_entity_index);
     }
 }

solitaire_engine/src/game_plugin/mod.rs

@@ -75,6 +75,17 @@ pub struct GameMutation;
 #[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
 pub struct NewGameRequestWriters;
 
+/// Self-ambiguous set for writers of `UndoRequestEvent` — same rationale as
+/// [`NewGameRequestWriters`]: consumers drain the queue, append order is
+/// meaningless (#143).
+#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct UndoRequestWriters;
+
+/// Self-ambiguous set for writers of `InfoToastEvent` — toasts queue in
+/// arrival order and any same-frame order is fine (#143).
+#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct InfoToastWriters;
+
 /// Persistence path for the in-progress game state file. `None` disables I/O.
 #[derive(Resource, Debug, Clone)]
 pub struct GameStatePath(pub Option<PathBuf>);
@@ -233,7 +244,14 @@ impl Plugin for GamePlugin {
                     .chain()
                     .in_set(GameMutation),
             )
-            .add_systems(Update, check_no_moves.after(GameMutation))
+            .add_systems(
+                Update,
+                check_no_moves
+                    .after(GameMutation)
+                    .before(crate::card_plugin::BoardVisuals)
+                    .in_set(InfoToastWriters)
+                    .ambiguous_with(InfoToastWriters),
+            )
             .add_systems(Update, record_replay_on_win.after(GameMutation))
             .add_systems(
                 Update,
@@ -244,14 +262,16 @@ impl Plugin for GamePlugin {
                     handle_game_over_button_input,
                 )
                     .after(GameMutation)
+                    .before(crate::ui_focus::FocusKeys)
                     .in_set(NewGameRequestWriters)
-                    .ambiguous_with(NewGameRequestWriters),
+                    .ambiguous_with(NewGameRequestWriters)
+                    .in_set(UndoRequestWriters)
+                    .ambiguous_with(UndoRequestWriters),
             )
             // Restore prompt: spawn the modal once the splash is gone,
             // route Continue / New Game intents back into the existing
             // GameMutation flow.
-            .add_systems(Update, spawn_restore_prompt_if_pending)
-            // All three pre-mutation game-state writers are chained: elapsed
+            // All pre-mutation game-state writers are chained: elapsed
             // time ticks first, settings sync next, then the restore prompt —
             // a deterministic spine instead of three unordered ResMut holders
             // (ambiguity burn-down, #143).
@@ -260,11 +280,13 @@ impl Plugin for GamePlugin {
                 (
                     tick_elapsed_time,
                     sync_settings_to_game,
+                    spawn_restore_prompt_if_pending,
                     handle_restore_prompt
                         .in_set(NewGameRequestWriters)
                         .ambiguous_with(NewGameRequestWriters),
                 )
                     .chain()
+                    .after(crate::settings_plugin::SettingsMutation)
                     .before(GameMutation),
             )
             .init_resource::<AutoSaveTimer>()

solitaire_engine/src/hud_plugin/mod.rs

@@ -54,6 +54,7 @@ use crate::time_attack_plugin::TimeAttackResource;
 use crate::ui_focus::{FocusGroup, Focusable};
 use crate::ui_modal::ModalScrim;
 use crate::ui_theme::SPACE_2;
+use crate::ui_theme::UiTextFx;
 use crate::ui_theme::{
     ACCENT_PRIMARY, ACCENT_SECONDARY, BG_ELEVATED, BG_ELEVATED_HI, BG_ELEVATED_PRESSED,
     BG_HUD_BAND, BORDER_SUBTLE, HighContrastBorder, MOTION_SCORE_PULSE_SECS,
@@ -153,6 +154,13 @@ pub struct HudColumn;
 #[derive(Component, Debug)]
 pub struct HudActionBar;
 
+/// Set wrapping the chained HUD button/popover interaction systems. Other
+/// keyboard consumers order themselves around it (e.g.
+/// [`crate::ui_focus::FocusKeys`] runs after) so input-consumption order is
+/// deterministic (#143).
+#[derive(bevy::ecs::schedule::SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct HudButtons;
+
 /// Marker on the text node inside each touch-layout action-bar button.
 /// Used by `resize_action_bar_labels` to update font size on window resize.
 #[derive(Component, Debug)]
@@ -467,25 +475,56 @@ impl Plugin for HudPlugin {
             // defensively so the HUD plugin works standalone in tests.
             .add_message::<WindowResized>()
             .add_systems(Startup, (spawn_hud_band, spawn_hud, spawn_action_buttons, spawn_hud_avatar))
-            .add_systems(Update, update_hud.after(GameMutation))
+            // HUD text updaters run as one deterministic chain (they write
+            // disjoint Text nodes, but Bevy can't prove it); update_hud also
+            // reads AutoCompleteState, so the chain sits after the
+            // auto-complete detect/drive chain (#143).
             .add_systems(
                 Update,
-                apply_hud_visibility.before(LayoutSystem::UpdateOnResize),
-            )
-            .add_systems(Update, restore_hud_on_modal)
-            .add_systems(Update, (update_hud_avatar, handle_avatar_button))
-            .add_systems(Update, update_won_previously.after(GameMutation))
-            .add_systems(Update, announce_auto_complete.after(GameMutation))
-            .add_systems(
-                Update,
-                update_selection_hud
-                    .after(GameMutation)
-                    .run_if(
+                (
+                    update_hud,
+                    update_selection_hud.run_if(
                         resource_exists_and_changed::<SelectionState>
                             .or(resource_exists_and_changed::<GameStateResource>),
                     ),
+                    update_won_previously,
+                )
+                    .chain()
+                    .after(GameMutation)
+                    .after(crate::auto_complete_plugin::AutoComplete)
+                    .in_set(UiTextFx)
+                    .ambiguous_with(UiTextFx),
+            )
+            // HUD chrome visibility: modal-restore writes HudVisibility, the
+            // applier consumes it, and the layout recompute reads it — a
+            // fixed chain instead of three racing systems (#143).
+            .add_systems(
+                Update,
+                (restore_hud_on_modal, apply_hud_visibility)
+                    .chain()
+                    .before(LayoutSystem::UpdateOnResize),
+            )
+            .add_systems(
+                Update,
+                (
+                    update_hud_avatar.after(crate::settings_plugin::SettingsMutation),
+                    handle_avatar_button.ambiguous_with(HudButtons),
+                ),
+            )
+            .add_systems(
+                Update,
+                announce_auto_complete
+                    .after(GameMutation)
+                    .after(crate::auto_complete_plugin::AutoComplete)
+                    .in_set(crate::game_plugin::InfoToastWriters)
+                    .ambiguous_with(crate::game_plugin::InfoToastWriters),
+            )
+            // Typography rescale touches HUD TextFont only, but orders after
+            // the board painters that resize card/label text (#143).
+            .add_systems(
+                Update,
+                update_hud_typography.after(crate::card_plugin::BoardVisuals),
             )
-            .add_systems(Update, update_hud_typography)
             .add_systems(
                 Update,
                 (
@@ -494,13 +533,19 @@ impl Plugin for HudPlugin {
                     advance_score_floater,
                 )
                     .chain()
-                    .after(GameMutation),
+                    .after(GameMutation)
+                    .in_set(UiTextFx)
+                    .ambiguous_with(UiTextFx)
+                    .ambiguous_with(crate::card_plugin::BoardVisuals),
             )
             .add_systems(
                 Update,
                 (start_streak_flourish, advance_streak_flourish)
                     .chain()
-                    .after(GameMutation),
+                    .after(GameMutation)
+                    .in_set(UiTextFx)
+                    .ambiguous_with(UiTextFx)
+                    .ambiguous_with(crate::card_plugin::BoardVisuals),
             )
             .add_systems(
                 Update,
@@ -508,10 +553,16 @@ impl Plugin for HudPlugin {
                     handle_new_game_button
                         .in_set(NewGameRequestWriters)
                         .ambiguous_with(NewGameRequestWriters),
-                    handle_undo_button,
+                    handle_undo_button
+                        .in_set(crate::game_plugin::UndoRequestWriters)
+                        .ambiguous_with(crate::game_plugin::UndoRequestWriters)
+                        .before(GameMutation),
                     handle_pause_button,
                     handle_help_button,
-                    handle_hint_button.after(GameMutation),
+                    handle_hint_button
+                        .after(GameMutation)
+                        .in_set(crate::game_plugin::InfoToastWriters)
+                        .ambiguous_with(crate::game_plugin::InfoToastWriters),
                     handle_modes_button,
                     handle_mode_option_click
                         .in_set(NewGameRequestWriters)
@@ -523,7 +574,10 @@ impl Plugin for HudPlugin {
                     handle_menu_backdrop_click,
                     close_menu_popover_on_escape,
                     paint_action_buttons,
-                ),
+                )
+                    .chain()
+                    .in_set(HudButtons)
+                    .before(crate::ui_focus::FocusKeys),
             )
             // Fade lives in `Last` so it always overrides whatever the
             // hover/paint pass set on `BackgroundColor` this frame.

solitaire_engine/src/schedule_checks.rs

@@ -32,13 +32,14 @@ mod tests {
     use crate::ui_focus::UiFocusPlugin;
     use crate::ui_modal::UiModalPlugin;
 
-    /// Legacy ambiguity backlog measured 2026-07-06 (issue #143). This
-    /// number may only decrease. If your change trips this assertion you
-    /// have added a pair of systems with conflicting data access and no
-    /// ordering edge — add `.before`/`.after` (order matters) or
-    /// `.ambiguous_with` (provably order-independent) at the registration
-    /// site. When triage lowers the real count, lower this constant too.
-    const AMBIGUITY_BASELINE: usize = 198;
+    /// The backlog (302 pairs on 2026-07-06) was burned down to ZERO the
+    /// same day (#143, PRs #146–#149) — this is now a hard gate. If your
+    /// change trips this assertion you have added a pair of systems with
+    /// conflicting data access and no ordering edge: add `.before`/`.after`
+    /// where order matters, or `.ambiguous_with` the relevant domain set
+    /// (BoardVisuals, MarkerVisuals, UiTextFx, HudButtons, writer sets)
+    /// where it provably does not. Do not raise this constant.
+    const AMBIGUITY_BASELINE: usize = 0;
 
     fn cluster_app() -> App {
         let mut app = App::new();
@@ -96,10 +97,12 @@ mod tests {
             }
         };
 
-        assert!(
-            count <= AMBIGUITY_BASELINE,
-            "system-order ambiguities grew: {count} > baseline {AMBIGUITY_BASELINE}. \
-             Add .before/.after or .ambiguous_with at the new registration site.",
+        assert_eq!(
+            count, AMBIGUITY_BASELINE,
+            "system-order ambiguities changed from the enforced baseline. \
+             Add .before/.after or .ambiguous_with at the new registration site \
+             (or, if the count legitimately dropped below a nonzero baseline, \
+             lower AMBIGUITY_BASELINE).",
         );
     }
 }

solitaire_engine/src/settings_plugin/mod.rs

@@ -79,6 +79,14 @@ pub struct PendingWindowGeometry {
 #[derive(Message, Debug, Clone)]
 pub struct SettingsChangedEvent(pub Settings);
 
+/// System set for the systems that mutate [`SettingsResource`] every frame
+/// (hotkeys and window-geometry persistence). Ordered before
+/// [`crate::game_plugin::GameMutation`]; readers of settings should sit
+/// after this set (directly, or transitively via `.after(GameMutation)`)
+/// so they observe the current frame's settings deterministically (#143).
+#[derive(SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct SettingsMutation;
+
 /// Marker on the root Settings panel entity.
 #[derive(Component, Debug)]
 pub struct SettingsPanel;
@@ -372,16 +380,37 @@ impl Plugin for SettingsPlugin {
             // also runs cleanly under `MinimalPlugins` (tests).
             .add_message::<WindowResized>()
             .add_message::<WindowMoved>()
+            // Settings changes land before game logic runs: the mutator
+            // chain (volume keys → geometry record → geometry persist) is a
+            // deterministic spine, and the whole set precedes GameMutation so
+            // every reader already ordered after GameMutation sees this
+            // frame's settings transitively (ambiguity burn-down, #143).
+            .configure_sets(
+                Update,
+                SettingsMutation
+                    .after(crate::layout::LayoutSystem::UpdateOnResize)
+                    .before(crate::game_plugin::GameMutation),
+            )
             .add_systems(
                 Update,
                 (
                     handle_volume_keys,
-                    toggle_settings_screen,
-                    scroll_settings_panel,
-                    crate::ui_modal::touch_scroll_panel::<SettingsPanelScrollable>,
                     record_window_geometry_changes,
                     persist_window_geometry_after_debounce,
-                ),
+                )
+                    .chain()
+                    .in_set(SettingsMutation),
+            )
+            .add_systems(
+                Update,
+                (
+                    toggle_settings_screen
+                        .before(crate::ui_focus::FocusKeys)
+                        .ambiguous_with(crate::hud_plugin::HudButtons),
+                    scroll_settings_panel,
+                    crate::ui_modal::touch_scroll_panel::<SettingsPanelScrollable>,
+                )
+                    .chain(),
             );
 
         if self.ui_enabled {

solitaire_engine/src/table_plugin.rs

@@ -85,6 +85,13 @@ pub struct HintPileHighlight {
 /// Registers the table background and pile-marker rendering.
 pub struct TablePlugin;
 
+/// Set wrapping the pile-marker painter chain (theme, hint highlights,
+/// visibility). Runs after [`crate::card_plugin::BoardVisuals`]; chrome-fx
+/// systems that touch `Visibility` on UI entities declare themselves
+/// ambiguous with it (#143).
+#[derive(bevy::ecs::schedule::SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct MarkerVisuals;
+
 impl Plugin for TablePlugin {
     fn build(&self, app: &mut App) {
         // Register WindowResized so the plugin works under MinimalPlugins in
@@ -101,10 +108,18 @@ impl Plugin for TablePlugin {
                 (
                     on_safe_area_changed.before(LayoutSystem::UpdateOnResize),
                     on_window_resized.in_set(LayoutSystem::UpdateOnResize),
-                    apply_theme_on_settings_change,
-                    apply_hint_pile_highlight,
-                    tick_hint_pile_highlights,
-                    sync_pile_marker_visibility.after(GameMutation),
+                    // Marker painters: deterministic chain after the card
+                    // paint pipeline — markers and cards share Sprite/
+                    // Transform access (#143).
+                    (
+                        apply_theme_on_settings_change,
+                        apply_hint_pile_highlight,
+                        tick_hint_pile_highlights,
+                        sync_pile_marker_visibility.after(GameMutation),
+                    )
+                        .chain()
+                        .in_set(MarkerVisuals)
+                        .after(crate::card_plugin::BoardVisuals),
                 ),
             );
     }

solitaire_engine/src/ui_focus.rs

@@ -117,6 +117,13 @@ pub struct FocusedButton(pub Option<Entity>);
 /// gains keyboard navigation without per-plugin wiring.
 pub struct UiFocusPlugin;
 
+/// Set on [`handle_focus_keys`], the focus-ring keyboard navigator. It runs
+/// AFTER every app-level keyboard consumer (HUD buttons/popovers, restore
+/// prompt, settings toggle) so Esc/Tab consumption order is defined instead
+/// of scheduler-dependent (#143).
+#[derive(bevy::ecs::schedule::SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct FocusKeys;
+
 impl Plugin for UiFocusPlugin {
     fn build(&self, app: &mut App) {
         app.init_resource::<FocusedButton>()
@@ -147,9 +154,19 @@ impl Plugin for UiFocusPlugin {
                 (
                     sync_focus_on_mouse_click,
                     clear_hud_focus_on_unhover,
-                    handle_focus_keys,
-                    update_focus_overlay,
-                    pulse_focus_overlay,
+                    handle_focus_keys
+                        .in_set(FocusKeys)
+                        .after(crate::game_plugin::GameMutation),
+                    update_focus_overlay
+                        .in_set(crate::ui_theme::UiTextFx)
+                        .ambiguous_with(crate::ui_theme::UiTextFx)
+                        .ambiguous_with(crate::card_plugin::BoardVisuals)
+                        .ambiguous_with(crate::table_plugin::MarkerVisuals),
+                    pulse_focus_overlay
+                        .after(crate::settings_plugin::SettingsMutation)
+                        .in_set(crate::ui_theme::UiTextFx)
+                        .ambiguous_with(crate::ui_theme::UiTextFx)
+                        .ambiguous_with(crate::card_plugin::BoardVisuals),
                 )
                     .chain(),
             );

solitaire_engine/src/ui_modal.rs

@@ -695,7 +695,12 @@ impl Plugin for UiModalPlugin {
                 advance_modal_enter,
                 paint_modal_buttons,
             )
-                .chain(),
+                .chain()
+                .after(crate::settings_plugin::SettingsMutation)
+                .in_set(crate::ui_theme::UiTextFx)
+                .ambiguous_with(crate::ui_theme::UiTextFx)
+                .ambiguous_with(crate::card_plugin::BoardVisuals)
+                .ambiguous_with(crate::hud_plugin::HudButtons),
         );
         // Click-outside-to-dismiss is independent of the open
         // animation chain — it reads `just_pressed(Left)` and runs

solitaire_engine/src/ui_theme.rs

@@ -698,3 +698,12 @@ mod tests {
         assert_eq!(scaled_duration(0.18, AnimSpeed::Instant), 0.0);
     }
 }
+
+/// System set for text/UI visual effects that animate `Transform`/`Sprite`
+/// on chrome entities (HUD score pulse, streak flourish, modal enter, focus
+/// ring). These never touch board entities, so members are declared
+/// `.ambiguous_with(BoardVisuals)` and `.ambiguous_with(UiTextFx)` — the
+/// entity domains are disjoint by construction and relative order within a
+/// frame is invisible (#143).
+#[derive(bevy::ecs::schedule::SystemSet, Debug, Clone, PartialEq, Eq, Hash)]
+pub struct UiTextFx;