feat: add seal.

src/app/niko/scene-components/sealcube.tsx

@@ -0,0 +1,27 @@
+import { useFrame, useLoader } from "@react-three/fiber";
+import { forwardRef, useImperativeHandle, useRef } from "react";
+import { Mesh, TextureLoader } from "three";
+
+const SealCube = forwardRef<Mesh>((props, ref) => {
+    const texture = useLoader(TextureLoader, 'niko/img/niko.jpg');
+    const meshRef = useRef<Mesh>(null);
+
+    useImperativeHandle(ref, () => meshRef.current!, []);
+
+    useFrame((state, delta) => {
+        if (meshRef.current) {
+            meshRef.current.rotation.x += delta * 0.5;
+            meshRef.current.rotation.y += delta * 0.5;
+        }
+    });
+
+    return (
+        <mesh ref={meshRef} position={[0, 3, 0]} castShadow receiveShadow>
+            <boxGeometry args={[0.85, 0.85, 0.85]} />
+            <meshBasicMaterial map={texture} depthWrite={true} />
+        </mesh>
+    );
+});
+SealCube.displayName = 'SealCube';
+
+export default SealCube;