MM-35133 trigger sync user immediately after change (#17579)

- ensure changes to user profile sync immediately
- refactor sync send

model/post.go

@@ -241,15 +241,15 @@ type GetPostsSinceOptions struct {
 	SortAscending            bool
 }
 
+type GetPostsSinceForSyncCursor struct {
+	LastPostUpdateAt int64
+	LastPostId       string
+}
+
 type GetPostsSinceForSyncOptions struct {
 	ChannelId       string
-	Since           int64 // inclusive
-	Until           int64 // inclusive
-	SortDescending  bool
 	ExcludeRemoteId string
 	IncludeDeleted  bool
-	Limit           int
-	Offset          int
 }
 
 type GetPostsOptions struct {
@@ -472,6 +472,14 @@ func (o *Post) IsRemote() bool {
 	return o.RemoteId != nil && *o.RemoteId != ""
 }
 
+// GetRemoteID safely returns the remoteID or empty string if not remote.
+func (o *Post) GetRemoteID() string {
+	if o.RemoteId != nil {
+		return *o.RemoteId
+	}
+	return ""
+}
+
 func (o *Post) IsJoinLeaveMessage() bool {
 	return o.Type == POST_JOIN_LEAVE ||
 		o.Type == POST_ADD_REMOVE ||