python env version fix for marimo

shells/default.nix

@@ -27,10 +27,6 @@
   };
 
   # Import all individual shell environments
-  rust = import ./rust.nix {inherit pkgs;};
   python = import ./python.nix {inherit pkgs;};
-  nodejs = import ./nodejs.nix {inherit pkgs;};
-  go = import ./go.nix {inherit pkgs;};
-  web = import ./web.nix {inherit pkgs;};
   devops = import ./devops.nix {inherit pkgs;};
 }

shells/python.nix

@@ -2,7 +2,7 @@
 # Usage: nix develop .#python   (drops into Nushell)
 {pkgs}: let
   # Use the latest Python available in nixpkgs
-  python = pkgs.python314;
+  python = pkgs.python313;
 in
   pkgs.mkShell {
     name = "python-marimo-dev";
@@ -11,6 +11,10 @@ in
       # Python interpreter
       python
 
+      # Tooling
+      black
+      pyrefly
+
       # Modern package manager
       uv