Add MixinHideEntitySystems to prevent world crash on cross-world teleport

[Dimotai]

Summary

Adds MixinHideEntitySystems to catch IllegalStateException: Invalid entity reference! in HideEntitySystems$AdventurePlayerSystem.tick(). This crash occurs when a player teleports between worlds and their entity reference is invalidated mid-tick, crashing the entire world thread and disconnecting all players.

Related issues

• None (new crash path not previously covered)

Type of change

• Bug fix (non-breaking)

Implementation details

Adds MixinHideEntitySystems.java targeting HideEntitySystems$AdventurePlayerSystem. Uses the same wrap-and-rethrow pattern as MixinStateSupport — injects at HEAD of tick(), wraps the original call in a try/catch for IllegalStateException, and logs a warning instead of crashing. Uses a ThreadLocal<Boolean> re-entry guard to prevent infinite recursion.

Stack trace from production server (15-20 concurrent players):

java.lang.IllegalStateException: Invalid entity reference!
    at com.hypixel.hytale.component.Ref.validate(Ref.java)
    at com.hypixel.hytale.component.Store.__internal_getArchetype(Store.java)
    at com.hypixel.hytale.component.CommandBuffer.getArchetype(CommandBuffer.java)
    at com.hypixel.hytale.server.core.modules.entity.system.HideEntitySystems$AdventurePlayerSystem.tick(HideEntitySystems.java)

Files changed:

• early/src/main/java/.../mixin/MixinHideEntitySystems.java (new)
• early/src/main/resources/refixes.mixins.json (added registration)

Checklist

• Code compiles successfully
• Pull request does not contain unrelated changes
• Changes follow this project's code style (Use spotlessApply when necessary)
• Changes are tested or will be tested after submission

Additional info

Tested on a production Hytale server (Histatu). The mixin loads cleanly and the server boots without errors. The fix only activates on the exact code path that would have crashed the world thread — normal tick execution is unaffected.