Fixed multithreading mutation issue

src/Server/Helper/SearchdomainHelper.cs

@@ -218,6 +218,7 @@ public class SearchdomainHelper(ILogger<SearchdomainHelper> logger, DatabaseHelp
             {
                 searchdomain.ReconciliateOrInvalidateCacheForNewOrUpdatedEntity(preexistingEntity);
             }
+            searchdomain.UpdateModelsInUse();
             return preexistingEntity;
         }
         else
@@ -243,6 +244,7 @@ public class SearchdomainHelper(ILogger<SearchdomainHelper> logger, DatabaseHelp
             };
             entityCache.Add(entity);
             searchdomain.ReconciliateOrInvalidateCacheForNewOrUpdatedEntity(entity);
+            searchdomain.UpdateModelsInUse();
             return entity;
         }
     }

src/Server/Searchdomain.cs

@@ -216,6 +216,11 @@ public class Searchdomain
         return queryEmbeddings;
     }
 
+    public void UpdateModelsInUse()
+    {
+        modelsInUse = GetModels([.. entityCache]);
+    }
+
     private static float EvaluateEntityAgainstQueryEmbeddings(Entity entity, Dictionary<string, float[]> queryEmbeddings)
     {
         List<(string, float)> datapointProbs = [];
@@ -237,6 +242,8 @@ public class Searchdomain
     public static List<string> GetModels(List<Entity> entities)
     {
         List<string> result = [];
+        lock (entities)
+        {
             foreach (Entity entity in entities)
             {
                 foreach (Datapoint datapoint in entity.datapoints)
@@ -251,6 +258,7 @@ public class Searchdomain
                     }
                 }
             }
+        }
         return result;
     }