T19: the main window lets the desktop through while Background opacity is under 1, blurred or clear as Background blur says, set at open and as the settings change; Ely's new ColumnShell::glass grounds every column and the title bar in the palette's glass, which the opacity sets, and the Ely pin moves to it past 27 of Ely's own commits; dialogs stay solid; the terminal paints no second ground; shot names the window's AppKit views

src/lib.rs

@@ -1,4 +1,5 @@
 pub mod app;
+pub mod blur;
 pub mod files;
 pub mod git;
 pub mod sessions;