fix(desktop): unfree CLI default, bar icon spacing, unified clock

Hardware findings on Latitude: nix-shell blocked unfree; whole-swap
bars collided icon+percentage; clock needed calcurse + one module.

- Export NIXPKGS_ALLOW_UNFREE=1 + ~/.config/nixpkgs/config.nix
- Mono Nerd face + trailing spaces on battery/volume icons (all bars)
- Single clock `HH:MM · Day DD Mon`; calcurse ships with waybar
- V3 queue entries for laptop re-check

Verification: V0 — nix flake check --no-build green; V2/V3 pending on
session (user-visible bar + CLI unfree).

themes/boreal/waybar.css

@@ -24,7 +24,9 @@
 @define-color bad       #E2818A;
 
 * {
-  font-family: "GeistMono Nerd Font", "Symbols Nerd Font";
+  /* Mono Nerd face for status glyphs (tight right bearings on the
+     proportional Symbols face make icon+percentage collide). */
+  font-family: "GeistMono Nerd Font", "Symbols Nerd Font Mono";
   font-size: 13px;
   font-weight: 500;
   border: none;
@@ -85,13 +87,12 @@ window#waybar {
 }
 #custom-nomarchy:hover { color: @accentAlt; }
 
-/* ── Clock — mono digits align; date recedes to frost-grey ───────────*/
+/* ── Clock — unified time · date ─────────────────────────────────────*/
 #clock {
   color: @text;
   font-weight: 600;
   padding-left: 4px;
 }
-#clock.date { color: @subtext; font-weight: 500; }
 
 /* ── Workspaces — dots that bloom to an aurora pill when active ───────*/
 #workspaces { padding: 0 2px; }