Edge build 0.2.10-edge.39

An edge build from the edge branch: new features before they're released.
Panels on the Edge update channel (Settings › Notifications) offer it.

Since v0.2.9:

• fix: backups no longer fail when the server removes a file while they're made
• style: import order and an optional chain
• feat: Discord messages with more to them
• feat: modules, step 1: helper containers next to a server, starting with BlueMap