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/animation.rs

@@ -33,6 +33,7 @@
 use std::f32::consts::PI;
 
 use bevy::prelude::*;
+use bevy::window::RequestRedraw;
 
 use super::curves::{MotionCurve, sample_curve};
 use super::timing::compute_duration;
@@ -232,10 +233,18 @@ pub(crate) fn advance_card_animations(
     time: Res<Time>,
     paused: Option<Res<PausedResource>>,
     mut q: Query<(Entity, &mut Transform, &mut CardAnimation)>,
+    mut redraw: MessageWriter<RequestRedraw>,
 ) {
     if paused.is_some_and(|p| p.0) {
         return;
     }
+    // Keep the winit event loop awake while any animation (including one
+    // still in its delay phase) needs per-frame ticks. Without this,
+    // Android's reactive_low_power focused_mode only wakes at its 100 ms
+    // ceiling and card slides render at ~10 fps.
+    if !q.is_empty() {
+        redraw.write(RequestRedraw);
+    }
     let dt = time.delta_secs();
 
     for (entity, mut transform, mut anim) in &mut q {