Add placeholder ghost UI, ghost component

Content.Client/Observer/GhostComponent.cs

@@ -0,0 +1,53 @@
+using Content.Client.UserInterface;
+using Content.Shared.Observer;
+using Robust.Client.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Network;
+using Robust.Shared.IoC;
+
+namespace Content.Client.Observer
+{
+    [RegisterComponent]
+    public class GhostComponent : SharedGhostComponent
+    {
+        private GhostGui _gui;
+
+#pragma warning disable 649
+        [Dependency] private readonly IGameHud _gameHud;
+#pragma warning restore 649
+
+        public override void OnRemove()
+        {
+            base.OnRemove();
+
+            _gui?.Dispose();
+        }
+
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null,
+            IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case PlayerAttachedMsg _:
+                    if (_gui == null)
+                    {
+                        _gui = new GhostGui();
+                    }
+                    else
+                    {
+                        _gui.Parent?.RemoveChild(_gui);
+                    }
+
+                    _gameHud.HandsContainer.AddChild(_gui);
+                    break;
+
+                case PlayerDetachedMsg _:
+                    _gui.Parent?.RemoveChild(_gui);
+                    break;
+            }
+        }
+    }
+}

Content.Client/UserInterface/GhostGui.cs

@@ -0,0 +1,18 @@
+using Robust.Client.UserInterface;
+using Robust.Client.UserInterface.Controls;
+using Robust.Shared.IoC;
+
+namespace Content.Client.UserInterface
+{
+    public class GhostGui : Control
+    {
+        public GhostGui()
+        {
+            IoCManager.InjectDependencies(this);
+
+            MouseFilter = MouseFilterMode.Ignore;
+
+            AddChild(new Label(){Text = "YES THIS IS GHOST WHOOOOOO"});
+        }
+    }
+}

Content.Shared/Observer/SharedGhostComponent.cs

@@ -0,0 +1,9 @@
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.Observer
+{
+    public class SharedGhostComponent : Component
+    {
+        public override string Name => "Ghost";
+    }
+}

Resources/Prototypes/Entities/mobs/observer.yml

@@ -15,3 +15,4 @@
   - type: Examiner
     DoRangeCheck: false
   - type: IgnorePause
+  - type: Ghost