LegacyLauncher/archive ? reverse-engineered prompt

I want to turn this old Java launcher source archive into something I can actually build and run locally.

Please clean up the project so the modules work together again, fix any broken or outdated code, and make sure the launcher starts properly with its bootstrap and bridge parts in place. If anything is missing or unclear, check the current docs online and use the most sensible modern Java and Gradle approach for an old codebase like this.

I mainly want a working desktop launcher experience, with the shared code organized cleanly, and the project building from the root without manual patching. If there are legacy bits that are only there for reference, keep them separate from the runnable parts so it is easy to understand what still works.

Make the result easy to compile, easy to launch, and leave me with a short note on what you fixed and how to run it.