Validate ShaderPrototype IDs (#38728)

* Convert all shader prototype string literals to protoids in overlays

* Convert more shader prototype literal strings to protoids

* Convert ValidatePrototypeId to ProtoId

* Later

Content.Client/Stealth/StealthSystem.cs

@@ -10,6 +10,8 @@ namespace Content.Client.Stealth;
 
 public sealed class StealthSystem : SharedStealthSystem
 {
+    private static readonly ProtoId<ShaderPrototype> Shader = "Stealth";
+
     [Dependency] private readonly IPrototypeManager _protoMan = default!;
     [Dependency] private readonly SharedTransformSystem _transformSystem = default!;
     [Dependency] private readonly SpriteSystem _sprite = default!;
@@ -20,7 +22,7 @@ public sealed class StealthSystem : SharedStealthSystem
     {
         base.Initialize();
 
-        _shader = _protoMan.Index<ShaderPrototype>("Stealth").InstanceUnique();
+        _shader = _protoMan.Index(Shader).InstanceUnique();
 
         SubscribeLocalEvent<StealthComponent, ComponentShutdown>(OnShutdown);
         SubscribeLocalEvent<StealthComponent, ComponentStartup>(OnStartup);