refactor: move state migration to pre-flight, fix XDG hardcoding, and prevent Nix store bloat

modules/home/theme-files.nix

@@ -1,4 +1,4 @@
-{ config, ... }:
+{ config, lib, ... }:
 
 {
   xdg.configFile."nomarchy/current/theme" = {
@@ -16,7 +16,20 @@
   xdg.configFile."nomarchy/branding/icon.txt".source = ../../assets/branding/icon.txt;
 
   # Expose all themes to the system via local share for script accessibility
-  xdg.dataFile."nomarchy/themes".source = ../../assets/themes;
+  # We filter out images to prevent Nix Store bloat
+  xdg.dataFile."nomarchy/themes".source = builtins.path {
+    name = "nomarchy-themes-no-images";
+    path = ../../assets/themes;
+    filter = path: type: 
+      let 
+        baseName = baseNameOf path;
+      in
+        ! (type == "regular" && (
+          lib.hasSuffix ".jpg" baseName || 
+          lib.hasSuffix ".png" baseName || 
+          lib.hasSuffix ".jpeg" baseName
+        ));
+  };
 
   # Nautilus python extensions
   xdg.dataFile."nautilus-python/extensions/localsend.py".source = ../../assets/nautilus-python/extensions/localsend.py;