fix(engine): emit RequestRedraw from animation systems — restores 60 fps card animation on Android

Commit 38e4c03 (shipped in v0.40.0) switched Android's focused_mode to
reactive_low_power(100 ms) on the premise that every animation tick
system writes RequestRedraw while it has active work. The writers were
never actually added — the diff only contained the WinitSettings change,
imports, and add_message registrations. Result: with no touch input,
nothing wakes the winit loop during a card slide except the 100 ms
fallback ceiling, so animations render at ~10 fps on Android. Desktop
and web keep Continuous mode, which is why only Android was affected
(reported by Rhys the day v0.40.0 shipped; confirmed absent on v0.39.1).

Adds the missing MessageWriter<RequestRedraw> to all seven systems the
original commit message named:
- advance_card_animations (CardAnimationPlugin)
- advance_card_anims (AnimationPlugin — deal/win cascade/slides)
- tick_shake_anim, tick_settle_anim, tick_foundation_flourish
  (FeedbackAnimPlugin)
- drive_toast_display (AnimationPlugin — toast countdown)
- drive_auto_complete (AutoCompletePlugin — step-interval keepalive)

Each writes one RequestRedraw per frame while active work exists
(including delay phases, which also need per-frame ticks). Regression
test asserts an active CardAnimation emits RequestRedraw and an idle
board does not.

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

solitaire_engine/src/card_animation/mod.rs

@@ -307,6 +307,49 @@ mod tests {
         );
     }
 
+    /// Regression test for the v0.40.0 Android animation-lag bug: commit
+    /// 38e4c03 switched Android to `reactive_low_power` focused_mode on the
+    /// premise that animation systems write `RequestRedraw` while active,
+    /// but the writers were never added — card slides rendered at the 100 ms
+    /// wake ceiling (~10 fps). Active animations MUST emit `RequestRedraw`
+    /// every frame; an idle board must not.
+    #[test]
+    fn active_card_animation_requests_redraw() {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(CardAnimationPlugin);
+
+        // Idle board: no redraw requests.
+        app.update();
+        assert!(
+            app.world().resource::<Messages<RequestRedraw>>().is_empty(),
+            "no RequestRedraw expected while no animation is active"
+        );
+
+        app.world_mut().spawn((
+            Transform::from_translation(Vec3::ZERO),
+            CardAnimation {
+                start: Vec2::ZERO,
+                end: Vec2::new(100.0, 0.0),
+                elapsed: 0.0,
+                duration: 1.0,
+                curve: MotionCurve::Responsive,
+                delay: 0.0,
+                start_z: 0.0,
+                end_z: 0.0,
+                z_lift: 0.0,
+                scale_start: 1.0,
+                scale_end: 1.0,
+            },
+        ));
+        app.update();
+        assert!(
+            !app.world().resource::<Messages<RequestRedraw>>().is_empty(),
+            "an active CardAnimation must write RequestRedraw each frame to \
+             sustain the reactive render loop"
+        );
+    }
+
     #[test]
     fn card_animation_instant_snaps_on_zero_duration() {
         let mut app = App::new();