theme: move the alarm colour from pink to mauve

Mocha's pink is a pastel. Filled at slab size against the near-black
Persona surfaces it went chalky rather than sharp, which is what made
hovered destructive buttons read as a washed-out red. Mauve is saturated
enough to bite against that ground and still cannot be confused with the
blue accent.

Applies across quickshell, Hyprland, dunst, fish and nvim. The GTK
overrides are dropped entirely — stock Catppuccin Mocha Blue already
paints those surfaces, and a hand-written destructive colour there was
one more thing to keep in step for no gain.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

gtk-3.0/gtk.css

@@ -1,7 +1,4 @@
-/* Catppuccin Mocha Blue carries the whole GTK3 palette itself, so there is no
- * surface override here — the Takemi branch only needed one because it was
- * painting Fluent's greys black. All that is left is the one place the rice
- * disagrees with stock Catppuccin: destructive actions are pink, matching the
- * shell's alarm colour. */
-@define-color destructive_bg_color #f38ba8;
-@define-color destructive_fg_color #11111b;
+/* Catppuccin Mocha Blue carries the whole GTK3 palette itself, so there is
+ * nothing to override here — the Takemi branch only needed this file because
+ * it was painting Fluent's greys black. Kept as a hook for the next time the
+ * rice disagrees with stock Catppuccin. */