Fix type-checking errors in snippets (code only, no .md)

This commit both:
- Fixes pre-existing mistakes in snippets, aka wrong code samples.
- Adds hidden (`@hide`) statements that do not appear in the docs,
  but satisfy typecheckers.

qdrant-landing/content/documentation/headless/snippets/create-shard/create-named-shard-default/go.go

@@ -12,6 +12,8 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.CreateShardKey(context.Background(), "{collection_name}", &qdrant.CreateShardKey{
 		ShardKey: qdrant.NewShardKey("default"),
 	})

qdrant-landing/content/documentation/headless/snippets/create-shard/create-named-shard-for-promotion/go.go

@@ -12,12 +12,14 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.CreateShardKey(
 		context.Background(),
 		"{collection_name}",
 		&qdrant.CreateShardKey{
 			ShardKey: qdrant.NewShardKey("default"),
-			InitialState: qdrant.ReplicaState_PARTIAL,
-		}
+			InitialState: qdrant.PtrOf(qdrant.ReplicaState_Partial),
+		},
 	)
 }

qdrant-landing/content/documentation/headless/snippets/create-shard/create-named-shard-for-promotion/java.java

@@ -7,6 +7,7 @@ import io.qdrant.client.QdrantGrpcClient;
 import io.qdrant.client.grpc.Collections.CreateShardKey;
 import io.qdrant.client.grpc.Collections.CreateShardKeyRequest;
 import io.qdrant.client.grpc.Collections.ReplicaState;
+import io.qdrant.client.grpc.Common.Filter;
 
 public class Snippet {
         public static void run() throws Exception {
@@ -17,7 +18,7 @@ public class Snippet {
                                 .setCollectionName("{collection_name}")
                                 .setRequest(CreateShardKey.newBuilder()
                                                 .setShardKey(shardKey("default"))
-                                                .setInitialState(ReplicaState.PARTIAL)
+                                                .setInitialState(ReplicaState.Partial)
                                                 .build())
                                 .build()).get();
         }

qdrant-landing/content/documentation/headless/snippets/create-shard/create-named-shard/go.go

@@ -12,6 +12,8 @@ func Main() {
 		Port: 6334,
 	})
 
+	if err != nil { panic(err) } // @hide
+
 	client.CreateShardKey(context.Background(), "{collection_name}", &qdrant.CreateShardKey{
 		ShardKey: qdrant.NewShardKey("{shard_key}"),
 	})