feat: file permission.

controllers/lesson_plan.go

@@ -74,8 +74,11 @@ func (lc *LessonPlanController) Upload(c *gin.Context) {
 		return
 	}
 	tempPath := tempFile.Name()
+	tempClosed := false
 	defer func() {
-		_ = tempFile.Close()
+		if !tempClosed {
+			_ = tempFile.Close()
+		}
 		if _, statErr := os.Stat(tempPath); statErr == nil {
 			_ = os.Remove(tempPath)
 		}
@@ -104,6 +107,11 @@ func (lc *LessonPlanController) Upload(c *gin.Context) {
 
 	storedFilename := buildStoredLessonPlanFilename(md5Value, fileHeader.Filename)
 	finalPath := filepath.Join(lessonPlanStorageDir, storedFilename)
+	if err := tempFile.Close(); err != nil {
+		writeError(c, http.StatusInternalServerError, "failed to finalize upload")
+		return
+	}
+	tempClosed = true
 	if err := os.Rename(tempPath, finalPath); err != nil {
 		writeError(c, http.StatusInternalServerError, "failed to finalize upload")
 		return