feat: add working watchdog cycle

internal/database/functions.go

@@ -19,3 +19,7 @@ func GetFiles(db *gorm.DB) ([]File, error) {
 func RegisterFile(db *gorm.DB, f File) error {
 	return db.Create(&f).Error
 }
+
+func DeregisterFile(db *gorm.DB, f File) error {
+	return db.Delete(&f).Error
+}