Add C/C++ libraries for Python venv with compiled packages support

nixos/modules/development.nix

@@ -24,6 +24,14 @@
     selectedPackages =
       lib.concatMap (lang: languagePackages.${lang} or []) cfg.languages;
 
+    # C/C++ libraries needed for compiled Python packages (numpy, etc.)
+    pythonDevLibraries = with pkgs;
+      lib.optionals (lib.elem "python" cfg.languages) [
+        glibc
+        stdenv.cc.cc.lib
+        libxcrypt
+      ];
+
   in lib.mkIf cfg.enable {
 
     # Core development tools
@@ -37,7 +45,16 @@
       cmake
       ripgrep
       jq
-    ] ++ selectedPackages;
+    ] ++ selectedPackages ++ pythonDevLibraries;
+
+    # Set library paths for venv compatibility with compiled packages
+    environment.variables = lib.mkIf (lib.elem "python" cfg.languages) {
+      LD_LIBRARY_PATH = lib.makeLibraryPath (with pkgs; [
+        glibc
+        stdenv.cc.cc.lib
+        libxcrypt
+      ]);
+    };
 
     # Enable container support (optional)
     #virtualisation.docker.enable = true;