Content update for UI prediction (#27214)

* Content update for UI refactor

* Big update

* Sharing

* Remaining content updates

* First big update

* Prototype updates

* AUGH

* Fix UI comp ref

* Cleanup

- Fix predicted message, fix item slots, fix interaction range check.

* Fix regressions

* Make this predictive

idk why it wasn't.

* Fix slime merge

* Merge conflict

* Fix merge

Content.Server/Instruments/InstrumentComponent.cs

@@ -1,6 +1,7 @@
 using Content.Server.UserInterface;
 using Content.Shared.Instruments;
 using Robust.Shared.Player;
+using ActivatableUIComponent = Content.Shared.UserInterface.ActivatableUIComponent;
 
 namespace Content.Server.Instruments;
 
@@ -16,9 +17,9 @@ public sealed partial class InstrumentComponent : SharedInstrumentComponent
     [ViewVariables] public uint LastSequencerTick = 0;
 
     // TODO Instruments: Make this ECS
-    public ICommonSession? InstrumentPlayer =>
+    public EntityUid? InstrumentPlayer =>
         _entMan.GetComponentOrNull<ActivatableUIComponent>(Owner)?.CurrentSingleUser
-        ?? _entMan.GetComponentOrNull<ActorComponent>(Owner)?.PlayerSession;
+        ?? _entMan.GetComponentOrNull<ActorComponent>(Owner)?.PlayerSession.AttachedEntity;
 }
 
 [RegisterComponent]