Version 1.3.1 of SPGKit has been released.
This update resolves a build configuration issue that affected projects using Swift 5.9.
In previous versions, the package failed to compile because the Swift Package Manager setup did not correctly handle the interoperability between Swift and C++ sources. As a result, users on Swift 5.9 encountered build errors when integrating the library.
The fix applies the proper configuration for Swift/C++ interop, following the approach described in the Swift documentation. With this adjustment, the package now builds successfully on Swift 5.9 and later.
As part of this change, the minimum supported Swift version is now 5.9.
No other functionality has been modified in this release.