Entity Cleaner

• Refactored the project to use the Singleplayer Library, allowing the same codebase to seamlessly support both singleplayer and multiplayer.
• Removed duplicate logic that previously existed for separate singleplayer and multiplayer implementations.
• Removed the singleplayer/ and multiplayer/ folders.
• Introduced a single unified folder structure to handle both environments, making the project easier to maintain, install, and contribute to.
• Reduced code complexity and overall project size by eliminating redundant files.

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