fix(mako): deploy themed config to ~/.config/mako/config

`core/home/config/nomarchy/default/mako/core.ini` defines the Nomarchy
notification UX — urgency rules, app filters (Spotify silenced),
do-not-disturb mode, and button handlers for "Setup Wi-Fi" / "Update
System" / "Learn Keybindings" notifications. The file was deployed via
the bulk `nomarchy/` dir to
`~/.config/nomarchy/default/mako/core.ini`, but mako reads
`~/.config/mako/config` by default and `autostart.conf` launches it
without `--config`. So mako ran with stock defaults and the entire
themed UX was inert.

Added an explicit `xdg.configFile."mako/config".source` line in
core/home/configs.nix pointing at the existing themed file. mako now
picks up the Nomarchy rules out of the box.

Found during Pillar 8 audit of the desktop stack.

core/home/configs.nix

@@ -51,7 +51,15 @@ let
 
 in
 {
-  xdg.configFile = configMappings;
+  xdg.configFile = configMappings // {
+    # mako reads ~/.config/mako/config by default. The themed Nomarchy
+    # config (urgency rules, app filters, button handlers) lives under
+    # nomarchy/default/mako/core.ini for organizational reasons, so wire
+    # it explicitly here. Without this, mako silently falls back to its
+    # built-in defaults and every Nomarchy notification customization is
+    # inert.
+    "mako/config".source = lib.mkDefault ./config/nomarchy/default/mako/core.ini;
+  };
 
   home.file.".XCompose" = lib.mkDefault {
     source = ./config/nomarchy/default/xcompose;