feat(validation): show toast notification when GLB errors are detected on reload

src/main/java/com/tiedup/remake/client/gltf/diagnostic/GlbValidationReloadListener.java

@@ -6,6 +6,9 @@ import java.io.InputStream;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.components.toasts.SystemToast;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.Resource;
 import net.minecraft.server.packs.resources.ResourceManager;
@@ -129,6 +132,21 @@ public class GlbValidationReloadListener
             "[GltfValidation] Validated {} GLBs: {} passed, {} with warnings, {} with errors",
             total, passed, withWarnings, withErrors
         );
+
+        // Show toast notification for errors so artists don't have to check logs
+        if (withErrors > 0) {
+            int errorCount = withErrors;
+            Minecraft.getInstance().tell(() ->
+                Minecraft.getInstance().getToasts().addToast(
+                    SystemToast.multiline(
+                        Minecraft.getInstance(),
+                        SystemToast.SystemToastIds.PACK_LOAD_FAILURE,
+                        Component.literal("TiedUp! GLB Validation"),
+                        Component.literal(errorCount + " model(s) have errors. Run /tiedup validate")
+                    )
+                )
+            );
+        }
     }
 
     private static boolean hasWarnings(GlbValidationResult result) {