Add Java path configuration and input handling

- Introduced a new input field for Java path in the launcher UI.
- Updated the main process to handle saving and loading of the Java path.
- Enhanced game launch functionality to accept a Java path parameter.
- Added Java detection logic to find the Java executable on the system.
- Created a .gitignore file to exclude build artifacts and dependencies.

.gitignore

@@ -0,0 +1,2 @@
+dist/*
+node_modules/*