fix: use recursiveUpdate instead of // to preserve packages.default

The // operator does shallow merge, so packages.x86_64-linux.test-vm
overwrote the entire packages.x86_64-linux attrset, losing the default
package. nixpkgs.lib.recursiveUpdate properly merges nested attrsets.

flake.nix

@@ -12,6 +12,7 @@
       nixpkgs,
       flake-utils,
     }:
+    nixpkgs.lib.recursiveUpdate
     (flake-utils.lib.eachDefaultSystem (
       system:
       let
@@ -66,13 +67,10 @@
           ];
 
           postInstall = ''
-            # Create the destination
             mkdir -p $out/share/rhemawave
-           
-            # Copy everything from your local share/rhemawave/* into the store
             cp -r share/rhemawave/* $out/share/rhemawave/
           '';
-          
+
           meta = with pkgs.lib; {
             description = "RhemaWave kiosk application";
             license = licenses.unfree;
@@ -96,12 +94,11 @@
             echo ""
             echo "Build:  go build -o bin/rhemawave rhemawave.go"
             echo "Run:    ./bin/rhemawave"
-            echo "Reset:  ./dev_scripts/reset.sh"
           '';
         };
       }
     ))
-    // {
+    {
       nixosModules.default = import ./nixos/module.nix self;
 
       nixosConfigurations.test-vm = nixpkgs.lib.nixosSystem {