constitution update

docs/constitution.md

@@ -16,6 +16,17 @@
 - No blank lines between code blocks; keep markdown examples tight.
 - Minimize comments; prefer clear naming and shared helpers (`modules/factories/mkserver.nix`, `modules/factories/mkscript.nix`) to avoid duplication.
 - Use business-level, technology-agnostic language in AI docs; reserve implementation detail for module code.
+- Nix structure: flatten single-child attribute sets into their full path; keep multi-child sets nested for readability; merge siblings under a shared parent; flatten the shallowest subtree first to reduce indentation without losing clarity.
+```nix
+config.services.jellyfin.enable = true; # preferred single-leaf form
+config.services = {
+  nginx.enable = true;
+  jellyfin = {
+    enable = true;
+    port = 1234;
+  };
+};
+```
 
 ## Terminology and Naming Standards
 - Module: A Nix module under `modules/<category>/<name>.nix` auto-imported into the system.