fix: correct UV mapping horizontal flip issue on cylindrical and spherical projections

src/lib/bakingUtils.ts

@@ -40,7 +40,7 @@ export function reprojectUVs(geometry: THREE.BufferGeometry, mappingType: 'plana
       const centeredZ = z - center.z;
       // atan2 returns -PI to PI. We want 0 to 1 around the cylinder.
       let angle = Math.atan2(centeredZ, centeredX);
-      u = (angle + Math.PI) / (2 * Math.PI);
+      u = 1.0 - ((angle + Math.PI) / (2 * Math.PI));
       v = 1.0 - ny;
     } else if (mappingType === 'sphere') {
       // Spherical projection
@@ -52,7 +52,7 @@ export function reprojectUVs(geometry: THREE.BufferGeometry, mappingType: 'plana
       const phi = Math.acos(centeredY / radius); // 0 to PI
       let theta = Math.atan2(centeredZ, centeredX); // -PI to PI
       
-      u = (theta + Math.PI) / (2 * Math.PI);
+      u = 1.0 - ((theta + Math.PI) / (2 * Math.PI));
       v = phi / Math.PI; // 0 at top, 1 at bottom
     } else if (mappingType === 'box') {
       // Simple box projection (pick dominant axis based on normal)