ci: verify package builds before creating PR

.gitea/workflows/nix-update.yml

@@ -140,6 +140,24 @@ env:
             git branch -D "${BRANCH_NAME}" 2>/dev/null || true
           fi
 
+      - name: Verify packages build
+        if: steps.update.outputs.has_updates == 'true'
+        run: |
+          PACKAGES="${{ steps.update.outputs.updated_packages }}"
+          echo "Verifying builds for: $PACKAGES"
+
+          # Parse comma-separated package list
+          IFS=', ' read -ra PKG_ARRAY <<< "$PACKAGES"
+          for pkg in "${PKG_ARRAY[@]}"; do
+            echo "━━━ Building $pkg ━━━"
+            if nix build .#$pkg; then
+              echo "✓ $pkg built successfully"
+            else
+              echo "❌ Build failed for $pkg"
+              exit 1
+            fi
+          done
+
       - name: Push branch and create pull request
         if: steps.update.outputs.has_updates == 'true'
         run: |