[achimmihca]

What does this PR do?

• Reintegrate changes from Melody Mania up to 2026-09-08.
  • 🎤 This is a major milestone for the project! 🌟
  • For details see Discord: https://discord.com/channels/957290213246390352/1129076709501698068

Noteworthy Changes

• fix Companion App connection issue Companion app broken with Malformed conecction request: wrong message type #579
• new approach for AI tools, built on OnnxRuntime and sherpa-onnx
  • Vocals isolation: UVR via sherpa-onnx
  • Speech recognition: Parakeet via sherpa-onnx
  • Pitch detection (song editor only): RMVPE via OnnxRuntime
  • Lyrics alignment (aka. forced alignment): Nvidia Nemo Forced Aligner (NFA) via OnnxRuntime
  • the AI models are not included in the build by default. You can build the main game from source with build.sh (resp. build.ps1) and parameter downloadAiModels
• refactoring of media playback to support different backends (not relevant for UltraStar Play, but Melody Mania supports Unity API, VLC, and AVPro)
• ffmpeg libraries are used to load all audio samples upfront in sing scene and song editor
  • ffmpeg libraries are not included in the build by default. You can build the main game from source with build.sh (resp. build.ps1) and parameter downloadFfmpegLibraries
• upgrade to Unity 6.5
  • Custom VisualElements have been migrated towards [UxmlElement] and [UxmlAttribute] annotations

Squashed Commits

I decided to save you the long history with thousands of commits.
Instead, there is just one squashed commit to get the current code base of Melody Mania.
Other commits in this PR are adjustments to make the code work again in UltraStar Play.

Closes Issue(s)

close #579
close #439
close #449
close #527
close #544

More

I will create a new release soon on GitHub with these changes.

Additional Notes

Melody Mania successfully funded a Kickstarter campaign for new platforms, hooray!
This PR is to align UltraStar Play with Melody Mania before tackling the next development steps.