Staff of Animation Fixes (#35491)

* staff of animation fixes and system

* requested changes

* size back to normal

* Update AnimateSpellSystem.cs

---------

Co-authored-by: ScarKy0 <106310278+ScarKy0@users.noreply.github.com>

Content.Shared/Magic/Systems/AnimateSpellSystem.cs

@@ -0,0 +1,48 @@
+using Content.Shared.Magic.Components;
+using Content.Shared.Physics;
+using Robust.Shared.Containers;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Systems;
+using System.Linq;
+
+namespace Content.Shared.Magic.Systems;
+
+public sealed class AnimateSpellSystem : EntitySystem
+{
+    [Dependency] private readonly SharedPhysicsSystem _physics = default!;
+    [Dependency] private readonly SharedTransformSystem _transform = default!;
+    [Dependency] private readonly SharedContainerSystem _container = default!;
+
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<AnimateComponent, MapInitEvent>(OnAnimate);
+    }
+
+    private void OnAnimate(Entity<AnimateComponent> ent, ref MapInitEvent args)
+    {
+        // Physics bullshittery necessary for object to behave properly
+
+        if (!TryComp<FixturesComponent>(ent, out var fixtures) || !TryComp<PhysicsComponent>(ent, out var physics))
+            return;
+
+        var xform = Transform(ent);
+        var fixture = fixtures.Fixtures.First();
+
+        _transform.Unanchor(ent); // If left anchored they are effectively stuck/immobile and not a threat
+        _physics.SetCanCollide(ent, true, true, false, fixtures, physics);
+        _physics.SetCollisionMask(ent, fixture.Key, fixture.Value, (int)CollisionGroup.FlyingMobMask, fixtures, physics);
+        _physics.SetCollisionLayer(ent, fixture.Key, fixture.Value, (int)CollisionGroup.FlyingMobLayer, fixtures, physics);
+        _physics.SetBodyType(ent, BodyType.KinematicController, fixtures, physics, xform);
+        _physics.SetBodyStatus(ent, physics, BodyStatus.InAir, true);
+        _physics.SetFixedRotation(ent, false, true, fixtures, physics);
+        _physics.SetHard(ent, fixture.Value, true, fixtures);
+        _container.AttachParentToContainerOrGrid((ent, xform)); // Items animated inside inventory now exit, they can't be picked up and so can't escape otherwise
+
+        var ev = new AnimateSpellEvent();
+        RaiseLocalEvent(ref ev);
+    }
+}
+
+[ByRefEvent]
+public readonly record struct AnimateSpellEvent;