fix: handle file.Close() errors in sprites command (errcheck)

cmd/sprites/main.go

@@ -232,14 +232,18 @@ func generateSprite(cat *SpriteCategory, iconSize int, suffix string) error {
 }
 
 // loadImage loads a PNG image from the given path
-func loadImage(path string) (image.Image, error) {
+func loadImage(path string) (img image.Image, err error) {
 	file, err := os.Open(path)
 	if err != nil {
 		return nil, err
 	}
-	defer file.Close()
+	defer func() {
+		if cerr := file.Close(); cerr != nil && err == nil {
+			err = cerr
+		}
+	}()
 
-	img, err := png.Decode(file)
+	img, err = png.Decode(file)
 	if err != nil {
 		return nil, err
 	}
@@ -295,7 +299,7 @@ func resizeAndCenter(src image.Image, targetSize int) *image.RGBA {
 }
 
 // saveImage saves an image to the given path as PNG
-func saveImage(img image.Image, path string) error {
+func saveImage(img image.Image, path string) (err error) {
 	// Ensure directory exists
 	dir := filepath.Dir(path)
 	if err := os.MkdirAll(dir, 0755); err != nil {
@@ -306,7 +310,11 @@ func saveImage(img image.Image, path string) error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() {
+		if cerr := file.Close(); cerr != nil && err == nil {
+			err = cerr
+		}
+	}()
 
 	return png.Encode(file, img)
 }