Add a `hoverEffect` utility to `boardgame-phaser` to simplify
handling pointerover and pointerout events. Refactor
`CardContainer` in `sts-like-viewer` to use this new utility and
centralize card dimensions in `CARD_CONFIG`.
dragDropEventEffect
Replace Phaser event emissions with a `DragDropCallback` in
`dragDropEventEffect` to provide a more explicit and type-safe API
for handling drag-and-drop interactions.