Improve Chat List Search and Refresh triggers

Currently the Chat List’s Search and Refresh actions are triggered based on swipe speed. This confuses users since it’s not very clear how to activate one action versus the other.

I suggest changing this to a swipe distance instead. For example:
- Search: trigger on a short swipe, around 10% of the viewport height.
- Refresh: trigger on a longer swipe, around 20–30% of the viewport height.