Telegram style message selection

### Your use case

#### What would you like to do?

I want to be able to easily select many messages with a long press.

#### Why would you like to do it?

To easily copy-paste or forward multiple messages without the selection flow interrupting the conversation view or requiring many extra taps.

#### How would you like to achieve it?

Long-pressing a message should immediately begin selection mode and create tickboxes. You should then be able to:

* tap additional messages to toggle selection
* swipe up/down to quickly select many messages
* continue scrolling normally while selecting

Actions like copy, forward, and delete should appear in the top bar.

The important part is keeping the UI visually stable and lightweight while selecting, instead of switching into a heavy modal workflow.

### Have you considered any alternatives?

The current approach works functionally, but feels slower and more disruptive for selecting many or non-adjacent messages. Checkbox-heavy or modal approaches used by many apps also tend to break conversational context.

### Additional context

I recommend looking at and copying Telegram’s UX for this. Its selection flow feels extremely natural because:

* selection is message-centric
* scrolling continues normally
* the layout barely changes
* multi-select remains fast even across long histories

It preserves spatial continuity and minimizes mode-switching, which makes bulk actions much more comfortable to use.

### Are you willing to provide a PR?

No

Start by locating the existing Android message-selection flow and compare it with the Telegram behavior described in the issue. Done means long-press selection preserves the conversation view, supports toggling messages, scrolling, and swipe selection, with copy, forward, and delete available in the top bar.

Written by the indexing model from the issue text.