Predict dumping (#32394)

* Predict dumping

- This got soaped really fucking hard.
- Dumping is predicted, this required disposals to be predicte.d
- Disposals required mailing (because it's tightly coupled), and a smidge of other content systems.
- I also had to fix a compnetworkgenerator issue at the same time so it wouldn't mispredict.

* Fix a bunch of stuff

* nasty merge

* Some reviews

* Some more reviews while I stash

* Fix merge

* Fix merge

* Half of review

* Review

* re(h)f

* lizards

* feexes

* feex

Content.Client/Decals/DecalSystem.cs

@@ -13,7 +13,7 @@ namespace Content.Client.Decals
         [Dependency] private readonly IOverlayManager _overlayManager = default!;
         [Dependency] private readonly SpriteSystem _sprites = default!;
 
-        private DecalOverlay _overlay = default!;
+        private DecalOverlay? _overlay;
 
         private HashSet<uint> _removedUids = new();
         private readonly List<Vector2i> _removedChunks = new();
@@ -31,6 +31,9 @@ namespace Content.Client.Decals
 
         public void ToggleOverlay()
         {
+            if (_overlay == null)
+                return;
+
             if (_overlayManager.HasOverlay<DecalOverlay>())
             {
                 _overlayManager.RemoveOverlay(_overlay);
@@ -44,6 +47,10 @@ namespace Content.Client.Decals
         public override void Shutdown()
         {
             base.Shutdown();
+
+            if (_overlay == null)
+                return;
+
             _overlayManager.RemoveOverlay(_overlay);
         }