Introduce runtime checks preventing the non-platform-specific version of OpenIddict.Client.SystemIntegration from being used on iOS/macOS/Mac Catalyst

src/OpenIddict.Abstractions/OpenIddictResources.resx

@@ -1680,6 +1680,9 @@ To apply post-logout redirection responses, create a class implementing 'IOpenId
   <data name="ID0448" xml:space="preserve">
     <value>An unknown error occurred while trying to start an AS web authentication session.</value>
   </data>
+  <data name="ID0449" xml:space="preserve">
+    <value>The generic version of the OpenIddict.Client.SystemIntegration package cannot be used on this platform. Make sure your application is referencing the correct version by using the appropriate OS-specific TFM (e.g on macOS, 'net8.0-macos10.15').</value>
+  </data>
   <data name="ID2000" xml:space="preserve">
     <value>The security token is missing.</value>
   </data>

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationConfiguration.cs

@@ -83,6 +83,15 @@ public sealed class OpenIddictClientSystemIntegrationConfiguration : IConfigureO
             throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0389));
         }
 
+#if !SUPPORTS_APPKIT && !SUPPORTS_UIKIT
+        // When running on iOS, Mac Catalyst or macOS, ensure the version compiled for these platforms is used.
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("ios"))         ||
+            RuntimeInformation.IsOSPlatform(OSPlatform.Create("maccatalyst")) ||
+            RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+        {
+            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0449));
+        }
+#endif
 #pragma warning disable CA1416
         // If explicitly set, ensure the specified authentication mode is supported.
         if (options.AuthenticationMode is OpenIddictClientSystemIntegrationAuthenticationMode.ASWebAuthenticationSession &&

src/OpenIddict.Client.SystemIntegration/OpenIddictClientSystemIntegrationExtensions.cs

@@ -40,6 +40,15 @@ public static class OpenIddictClientSystemIntegrationExtensions
             throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0389));
         }
 
+#if !SUPPORTS_APPKIT && !SUPPORTS_UIKIT
+        // When running on iOS, Mac Catalyst or macOS, ensure the version compiled for these platforms is used.
+        if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("ios"))         ||
+            RuntimeInformation.IsOSPlatform(OSPlatform.Create("maccatalyst")) ||
+            RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+        {
+            throw new PlatformNotSupportedException(SR.GetResourceString(SR.ID0449));
+        }
+#endif
         // Note: the OpenIddict activation handler service is deliberately registered as early as possible to
         // ensure protocol activations can be handled before another service can stop the initialization of the
         // application (e.g Dapplo.Microsoft.Extensions.Hosting.AppServices relies on an IHostedService to implement