Fixed scroll to new messages on chat open (#5369)

Signed-off-by: Kristina Fefelova <kristin.fefelova@gmail.com>

models/activity/src/index.ts

@@ -34,7 +34,8 @@ import {
   type IgnoreActivity,
   type Reaction,
   type SavedMessage,
-  type TxViewlet
+  type TxViewlet,
+  type ReplyProvider
 } from '@hcengineering/activity'
 import contact, { type Person } from '@hcengineering/contact'
 import core, {
@@ -264,6 +265,11 @@ export class TActivityMessagePreview extends TClass implements ActivityMessagePr
   presenter!: AnyComponent
 }
 
+@Model(activity.class.ReplyProvider, core.class.Doc, DOMAIN_MODEL)
+export class TReplyProvider extends TDoc implements ReplyProvider {
+  function!: Resource<(message: ActivityMessage) => Promise<void>>
+}
+
 export function createModel (builder: Builder): void {
   builder.createModel(
     TTxViewlet,
@@ -281,7 +287,8 @@ export function createModel (builder: Builder): void {
     TSavedMessage,
     TIgnoreActivity,
     TActivityReference,
-    TActivityMessagePreview
+    TActivityMessagePreview,
+    TReplyProvider
   )
 
   builder.mixin(activity.class.DocUpdateMessage, core.class.Class, view.mixin.ObjectPresenter, {