feat: 扩展精灵动画系统并新增 SpriteAnimator 组件

- 新增动画模式: breathe, bounce, walkLeft, walkRight, flip
- 新增 SpriteAnimator 组件，内置 tick 循环和居中渲染
- BuddyPanel 使用 SpriteAnimator 替代手动渲染

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/pokemon/src/index.ts

@@ -46,3 +46,4 @@ export { EggView } from './ui/EggView'
 export { EvolutionAnim } from './ui/EvolutionAnim'
 export { StatBar } from './ui/StatBar'
 export { SpeciesDetail } from './ui/SpeciesDetail'
+export { SpriteAnimator } from './ui/SpriteAnimator'