feature(theme): replace all color theme configs with stylix

modules/home-manager/niri.nix

@@ -2,7 +2,12 @@
 # come from modules/nixos/niri.nix. Outputs and input devices that differ
 # per machine live in hosts/<host>/niri.nix.
 
-{ lib, osConfig, ... }:
+{
+  config,
+  lib,
+  osConfig,
+  ...
+}:
 
 let
   # Mod+1..9 focus a workspace, Mod+Ctrl+1..9 move the column there
@@ -18,6 +23,9 @@ let
     _props.allow-when-locked = true;
     spawn-sh = cmd;
   };
+
+  # niri has no stylix target, so the colors are picked here
+  colors = config.lib.stylix.colors.withHashtag;
 in
 {
   wayland.windowManager.niri = {
@@ -61,9 +69,9 @@ in
         focus-ring = {
           on = { };
           width = 2;
-          active-color = "#4c566a";
-          inactive-color = "#2e3440";
-          urgent-color = "#a3be8c";
+          active-color = colors.base03;
+          inactive-color = colors.base00;
+          urgent-color = colors.base0B;
         };
 
         border.off = { };