feat: add pulsing animation to attack target tiles in Advance Wars

Introduce a breathing pulse effect (red fill + white border) for attack
target tiles to draw the player's eye when in "must pick a target" fire
mode. The previous static tint is preserved for the indirect-range preview
shown while a unit is merely selected.

- showAttackTiles now accepts optional { pulse: true } parameter
- Added tween-based animation with Sine.easeInOut breathing effect
- Properly clean up pulse tween in destroy() and clearOverlays()
- Updated AdvanceWarsGame to pass pulse: true when showing targets

src/games/advancewars/AdvanceWarsGame.js

@@ -424,7 +424,7 @@ export default class AdvanceWarsGame extends Phaser.Scene {
     const run = this.run;
     run.mode = 'target';
     run.targets = targets;
-    run.view.showAttackTiles(targets.map((t) => ({ x: t.x, y: t.y })));
+    run.view.showAttackTiles(targets.map((t) => ({ x: t.x, y: t.y })), { pulse: true });
   }
 
   onTargetClick(tile) {

src/games/advancewars/AdvanceWarsMapView.js

@@ -246,6 +246,7 @@ export class AdvanceWarsMapView {
 
   destroy() {
     this.flipTimer?.remove();
+    this.atkPulseTween?.stop();
     this.rt?.destroy();
     this.moveG?.destroy(); this.atkG?.destroy(); this.fogG?.destroy();
     this.pathG?.destroy(); this.cursor?.destroy();
@@ -492,15 +493,42 @@ export class AdvanceWarsMapView {
     }
   }
 
-  showAttackTiles(tiles) {
+  // pulse: true for "you must pick a target now" (entering FIRE target mode)
+  // — red fill + white border breathing to draw the eye. false (default)
+  // keeps the old static tint, used for the indirect-range preview shown
+  // while a unit is merely selected, before a move/target is committed to.
+  showAttackTiles(tiles, { pulse = false } = {}) {
+    this.atkPulseTween?.stop();
+    this.atkPulseTween = null;
     this.atkG.clear();
-    this.atkG.fillStyle(0xff3d3d, 0.42);
-    for (const { x, y } of tiles) {
-      this.atkG.fillRect(this.ox + x * this.tile + 1, this.oy + y * this.tile + 1, this.tile - 2, this.tile - 2);
+    if (!pulse) {
+      this.atkG.fillStyle(0xff3d3d, 0.42);
+      for (const { x, y } of tiles) {
+        this.atkG.fillRect(this.ox + x * this.tile + 1, this.oy + y * this.tile + 1, this.tile - 2, this.tile - 2);
+      }
+      return;
     }
+    const draw = (fillA, lineA) => {
+      this.atkG.clear();
+      this.atkG.fillStyle(0xff3d3d, fillA);
+      this.atkG.lineStyle(Math.max(2, this.tile * 0.06), 0xffffff, lineA);
+      for (const { x, y } of tiles) {
+        const px = this.ox + x * this.tile + 1, py = this.oy + y * this.tile + 1, s = this.tile - 2;
+        this.atkG.fillRect(px, py, s, s);
+        this.atkG.strokeRect(px, py, s, s);
+      }
+    };
+    const phase = { t: 0 };
+    draw(0.30, 0.55);
+    this.atkPulseTween = this.scene.tweens.add({
+      targets: phase, t: 1, duration: 550, yoyo: true, repeat: -1, ease: 'Sine.easeInOut',
+      onUpdate: () => draw(0.28 + phase.t * 0.34, 0.5 + phase.t * 0.5),
+    });
   }
 
   clearOverlays() {
+    this.atkPulseTween?.stop();
+    this.atkPulseTween = null;
     this.moveG.clear();
     this.atkG.clear();
     this.pathG.clear();