refactor(onitama): extract tweens into factory functions

Centralize Onitama animation logic by moving inline Phaser tweens
into a dedicated `tweens.ts` configuration file. This improves
reusability and cleans up spawners and renderers.

Also updated documentation to warn against adding interruptions to
looped tweens to prevent game logic hangs.

packages/onitama-game/src/scenes/OnitamaScene.ts

@@ -9,11 +9,11 @@ import type Phaser from "phaser";
 import {
   COLORS,
   FONTS,
-  ANIMATIONS,
   MENU_BUTTON,
   getBoardCenter,
   getCardLabelPosition,
   colorToStr,
+  createWinnerPulseTween,
 } from "@/config";
 import { prompts } from "@/game/onitama";
 import {
@@ -304,12 +304,6 @@ export class OnitamaScene extends GameHostScene<OnitamaState> {
 
     this.winnerOverlay.add(winText);
 
-    this.tweens.add({
-      targets: winText,
-      scale: 1.2,
-      duration: ANIMATIONS.winnerPulse,
-      yoyo: true,
-      repeat: 1,
-    });
+    createWinnerPulseTween(this, winText);
   }
 }