Eliminates WebGL bindBuffer/bindTexture spam from dual Application contexts.
Cat model now loads onto KiraAvatar's shared stage via onAppReady callback.
- Copied LittleCat model files to frontend/public/live2d/models/little-cat/
- Using the black alternate texture as default
- Created Live2DCat component that renders the model in a small canvas
- PetZone now shows a single Live2D cat instead of two SVG cats