refactor: Fleet and sw behind mkIf guards

sw/python.nix

@@ -18,10 +18,27 @@ let
   cfg = config.athenix.sw.python;
 in
 {
-  options.athenix.sw.python = {
-    enable = mkEnableOption "Python development tools (pixi, uv)" // {
-      default = true;
+  options.athenix.sw.python = lib.mkOption {
+    type = lib.types.submodule {
+      options = {
+        enable = lib.mkOption {
+          type = lib.types.bool;
+          default = true;
+          description = ''
+            Enable Python development tools (pixi, uv).
+
+            Provides:
+            - pixi: Fast, cross-platform package manager for Python
+            - uv: Extremely fast Python package installer and resolver
+
+            These tools manage project-based dependencies rather than global
+            Python packages, avoiding conflicts and improving reproducibility.
+          '';
+        };
+      };
     };
+    default = { };
+    description = "Python development environment configuration.";
   };
 
   config = mkIf cfg.enable {