Release 1.3.1: no setup window at launch, balanced spacing

[StevenACZ]

Summary

• On a Mac where Encaje is already set up, every launch showed the setup window and then the welcome for a few seconds: the shortcut listener started in a deferred task, so readiness was still false when launch decided whether to show the setup window. Launch now refreshes the model (which starts the listener when Accessibility is on) before that decision.
• The setup window no longer has a large gap above the icon and almost none under "Set up later": its height was measured without the transparent titlebar inset. The screen now owns its top spacing.
• Version 1.3.1, build 19.

Verification

• make check passes.
• Relaunched on a set-up Mac: no setup or welcome window appears.
• Measured on a test Mac: 45 pt above the icon and 29 pt under "Set up later" (was about 60 and 10).