외벽선 없는경우 지붕형상 설정 안되게 수정

src/hooks/roofcover/useRoofShapeSetting.js

@@ -167,9 +167,14 @@ export function useRoofShapeSetting(id) {
   ]
 
   const handleSave = () => {
-    let outerLines
+    let outerLines = canvas.getObjects().filter((obj) => obj.name === 'outerLine' && obj.visible)
     let direction
 
+    if (outerLines.length < 2) {
+      swalFire({ text: '외벽선이 없습니다.', icon: 'error' })
+      return
+    }
+
     switch (shapeNum) {
       case 1: {
         outerLines = saveRidge()