Relay 0.19.4

TL;DR: A fix for the interface growing on every launch, select all when importing projects, and steadier handoffs.

• The interface scale no longer grows a little more each time Relay starts.
• Importing projects has a "select all".
• Handing a thread straight back out right after bringing it home no longer fails with "already on its way".
• Much lighter on your disk while answers stream: a long thread no longer gets rewritten in full every second, only what changed.