Add call-on-services-ready attribute for service methods, and fix scene nullability (#900)

Dalamud/Plugin/Internal/PluginManager.cs

@@ -31,7 +31,7 @@ namespace Dalamud.Plugin.Internal;
 /// Class responsible for loading and unloading plugins.
 /// </summary>
 [ServiceManager.EarlyLoadedService]
-internal partial class PluginManager : IDisposable
+internal partial class PluginManager : IDisposable, IServiceType
 {
     /// <summary>
     /// The current Dalamud API level, used to handle breaking changes. Only plugins with this level will be loaded.
@@ -386,12 +386,8 @@ internal partial class PluginManager : IDisposable
 
         // Load plugins that want to be loaded during Framework.Tick, when drawing facilities are available
         loadTasks.Add(
-            Service<InterfaceManager>
+            Service<InterfaceManager.InterfaceManagerWithScene>
                 .GetAsync()
-                .ContinueWith(
-                    x => x.Result.SceneInitializeTask,
-                    TaskContinuationOptions.RunContinuationsAsynchronously)
-                .Unwrap()
                 .ContinueWith(
                     _ => Service<Framework>.Get().RunOnTick(
                         () => LoadPluginsSync(

Dalamud/Plugin/Internal/StartupPluginLoader.cs

@@ -10,7 +10,7 @@ namespace Dalamud.Plugin.Internal;
 /// Class responsible for loading plugins on startup.
 /// </summary>
 [ServiceManager.BlockingEarlyLoadedService]
-public class StartupPluginLoader
+public class StartupPluginLoader : IServiceType
 {
     private static readonly ModuleLog Log = new("SPL");
 

Dalamud/Plugin/Ipc/Internal/CallGate.cs

@@ -6,7 +6,7 @@ namespace Dalamud.Plugin.Ipc.Internal
     /// This class facilitates inter-plugin communication.
     /// </summary>
     [ServiceManager.EarlyLoadedService]
-    internal class CallGate
+    internal class CallGate : IServiceType
     {
         private readonly Dictionary<string, CallGateChannel> gates = new();