Add CultMesh document catalog mutations

src/GameCult.Mesh/CultMeshPrimitives.cs

@@ -1177,6 +1177,34 @@ namespace GameCult.Mesh
             return Document<TDocument>().Latest();
         }
 
+        /// <summary>Gets whether one typed document can be replaced by CLR type or same-schema alias.</summary>
+        public bool CanReplace<TDocument>()
+            where TDocument : class
+        {
+            return TryGetDocument<TDocument>(out var document) && document.CanReplace;
+        }
+
+        /// <summary>Replaces one typed document by CLR type or same-schema alias.</summary>
+        public Task ReplaceAsync<TDocument>(TDocument value)
+            where TDocument : class
+        {
+            return Document<TDocument>().ReplaceAsync(value);
+        }
+
+        /// <summary>Gets whether one typed document can submit client predictions by CLR type or same-schema alias.</summary>
+        public bool CanSubmitPrediction<TDocument>()
+            where TDocument : class
+        {
+            return TryGetDocument<TDocument>(out var document) && document.CanSubmitPrediction;
+        }
+
+        /// <summary>Submits a client prediction for one typed document by CLR type or same-schema alias.</summary>
+        public Task SubmitPredictionAsync<TDocument>(TDocument value)
+            where TDocument : class
+        {
+            return Document<TDocument>().SubmitPredictionAsync(value);
+        }
+
         /// <summary>Watches one typed document by CLR type or same-schema alias.</summary>
         public Observable<TDocument> Watch<TDocument>()
             where TDocument : class

src/GameCult.Mesh/docs/public-api.md

@@ -178,7 +178,10 @@ portable machinery that makes it feel native.
   schema version, and resolves same-schema CLR aliases by delegating to
   `CultMeshDocumentHandle<TDocument>.AsSchemaAlias<TAlias>()`. Domain facades
   can expose `Document<T>()`, `DocumentBySchema(...)`, `LatestAsync<T>()`, and
-  `Watch<T>()` without owning schema dictionaries or alias serializers.
+  `Watch<T>()` without owning schema dictionaries or alias serializers. Mutable
+  facades can also call `ReplaceAsync<T>(...)` or
+  `SubmitPredictionAsync<T>(...)` directly on the catalog when they only need
+  the schema-aliased operation and not the intermediate handle.
 - `CultMeshCollectionHandle<TDocument>` is the typed reactive edge for
   multi-record state. It exposes one `LatestAsync()` collection snapshot and a
   `WatchChanges()` stream while hiding whether the backing source is an