Update CI workflow to use NixOS, configure Attic cache, and enhance build summary

.github/workflows/build-schemes.yml

@@ -9,7 +9,9 @@ on:
 
 jobs:
   build-schemes:
-    runs-on: ubuntu-latest
+    runs-on: nixos
+    env:
+      HOSTNAME: server
     
     steps:
     - uses: actions/checkout@v4
@@ -44,9 +46,38 @@ jobs:
         wait
         echo "All schemes built successfully!"
     
+    - name: Configure Attic cache
+      run: |
+        # Configure attic client to use your cache server
+        attic login servidos https://cache.servidos.lat ${{ secrets.ATTIC_TOKEN }}
+    
+    - name: Push schemes to cache
+      run: |
+        echo "Pushing all scheme builds to cache..."
+        # Push all built derivations to cache
+        if ls result* 1> /dev/null 2>&1; then
+          attic push servidos:nixos result*
+        fi
+        
+        # Push each scheme build individually for better cache granularity
+        for scheme in ${{ steps.schemes.outputs.schemes }}; do
+          echo "Pushing scheme $scheme to cache..."
+          nix build .#nixosConfigurations.${HOSTNAME}.config.system.build.toplevel \
+            --override-input stylix-scheme $scheme \
+            --print-out-paths | attic push servidos:nixos --stdin
+        done
+        echo "All schemes pushed to cache successfully!"
+    
     - name: Upload build artifacts
       uses: actions/upload-artifact@v4
       with:
         name: nixos-configurations
         path: ./result-*
         retention-days: 7
+    
+    - name: Summary
+      run: |
+        echo "✅ Color scheme builds completed successfully!"
+        echo "- Built all ${{ steps.schemes.outputs.schemes }} schemes"
+        echo "- Pushed all builds to Atticd cache"
+        echo "- Uploaded artifacts for backup"