Retint the scrims to the v5 canvas, quick connect at the spec's 60%

Five scrim hardcodes still dimmed through the old canvas #0E1220; they
now sit on #05050A. Each keeps its alpha except QuickConnect's backdrop,
which the v5 spec pins at rgba(5,5,10,0.6) — its essay drops from 80% to
60% of Canvas to match.

src/DodoSSH.Client.App/Views/HostKeyCard.axaml

@@ -45,7 +45,7 @@
     80% of Canvas, written out because a scrim is a brush with an alpha and the palette holds no alpha
     variant of a surface; the pre-multiplied ones there are accent washes.
   -->
-  <Border Background="#CC0E1220">
+  <Border Background="#CC05050A">
     <Panel>
 
       <!-- ============ UNKNOWN HOST KEY ============ -->