fix(engine): snap cards directly on window resize

on_window_resized was firing StateChangedEvent on every WindowResized
event. That ran sync_cards_on_change → update_card_entity, which
inserts a CardAnim slide tween for every card whose target moves >1
unit. During a corner drag the resize fires every frame, retargeting
the slide each time from the cards' current mid-tween positions, so
cards never reach steady state — the visible "snap back and forth"
jitter reported during the 2026-04-29 smoke test.

Replace the StateChangedEvent emit with a direct snap path:

- Add LayoutSystem::UpdateOnResize SystemSet in layout.rs so cross-
  plugin ordering is explicit (Bevy's automatic conflict-based order
  only forces non-parallel execution, not a particular order).
- table_plugin::on_window_resized: drop the StateChangedEvent emit;
  mark the system in_set(LayoutSystem::UpdateOnResize). It already
  snaps backgrounds and pile markers directly, so this aligns cards
  with the same instant-snap policy.
- card_plugin: new snap_cards_on_window_resize system listens for
  WindowResized, runs .after(LayoutSystem::UpdateOnResize), writes
  fresh transforms via the existing card_positions() helper, and
  removes any in-flight CardAnim. It also reapplies the stock-empty
  indicator so the "↺" label's font_size (derived from
  layout.card_size.x) still rescales on resize.

Other StateChangedEvent listeners — start_settle_anim,
detect_auto_complete, clear_selection_on_state_change, check_no_moves,
reset_hint_cycle_on_state_change, clear_right_click_highlights — no
longer fire spuriously on resize. They should not fire on a layout
change anyway; that was a pre-existing minor bug masked by the
jitter.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

solitaire_engine/src/table_plugin.rs

@@ -10,7 +10,7 @@ use solitaire_core::card::Suit;
 use solitaire_core::pile::PileType;
 
 use crate::events::{HintVisualEvent, StateChangedEvent};
-use crate::layout::{compute_layout, Layout, LayoutResource};
+use crate::layout::{compute_layout, Layout, LayoutResource, LayoutSystem};
 #[cfg(test)]
 use crate::layout::TABLE_COLOUR;
 use crate::settings_plugin::{SettingsChangedEvent, SettingsResource};
@@ -69,7 +69,7 @@ impl Plugin for TablePlugin {
             .add_systems(
                 Update,
                 (
-                    on_window_resized,
+                    on_window_resized.in_set(LayoutSystem::UpdateOnResize),
                     apply_theme_on_settings_change,
                     apply_hint_pile_highlight,
                     tick_hint_pile_highlights,
@@ -275,12 +275,10 @@ fn spawn_pile_markers(commands: &mut Commands, layout: &Layout) {
     }
 }
 
-#[allow(clippy::too_many_arguments)]
 #[allow(clippy::type_complexity)]
 fn on_window_resized(
     mut events: MessageReader<WindowResized>,
     mut layout_res: Option<ResMut<LayoutResource>>,
-    mut state_changed: MessageWriter<StateChangedEvent>,
     mut backgrounds: Query<
         (&mut Sprite, &mut Transform),
         (With<TableBackground>, Without<PileMarker>),
@@ -311,8 +309,12 @@ fn on_window_resized(
         }
     }
 
-    // Reposition card sprites to the new layout.
-    state_changed.write(StateChangedEvent);
+    // Card sprites are repositioned by `card_plugin::snap_cards_on_window_resize`
+    // running `.after(LayoutSystem::UpdateOnResize)` — that system snaps card
+    // transforms directly to the new layout instead of going through
+    // `StateChangedEvent → sync_cards → CardAnim` which would retarget the
+    // slide tween every frame during a corner drag (the visible "snap back
+    // and forth" jitter).
 }
 
 // ---------------------------------------------------------------------------