Lite version:
This project is currently licensed under PolyForm Shield License 1.0.0.
More legal information can be found on Modrinth page.
This project was accidentally "attached" with a GPL license text. It should be noted that this project has never been licensed by GPL so far. The source code was never distributed before the project was first made public, and its source code was not distributed under the GPL license before that. Therefore, all the code in this project so far (also before) is (also was) not licensed under GPL. This was a mistake. This is a copyright notice.
Once I decide to quit, the license will be changed to LGPL so that this project doesn't become a corpse. This is a promise.