update: system update & refactor

# Breaking Changes
- sops location movod to "system/dev/<dev-name>/sops/sops-conf.nix"
- flake devices declaration changes
- whole flake update

system/dev/dn-pre7780/utility/default.nix

@@ -0,0 +1,8 @@
+{
+  imports = [
+    ../../../modules/localsend.nix
+    ./airplay.nix
+    ./davinci-resolve.nix
+    ./blender.nix
+  ];
+}