Rename Helm chart to api7ee-demo-k8s

- Changed chart name from api7ee to api7ee-demo-k8s in Chart.yaml
- Renamed helm/api7ee directory to helm/api7ee-demo-k8s
- Updated all references in build.yml workflow
- Updated all references in helm-release.yml workflow
- Updated main README.md with new chart name
- Updated Helm chart README with new chart name
- Verified all old references have been replaced
- Chart packages correctly as api7ee-demo-k8s-{version}.tgz

README.md

@@ -149,13 +149,13 @@ helm repo update
 
 ```bash
 # Install with default values
-helm install my-api7ee api7ee/api7ee --namespace api7ee --create-namespace
+helm install my-api7ee api7ee/api7ee-demo-k8s --namespace api7ee --create-namespace
 
 # Install with custom values
-helm install my-api7ee api7ee/api7ee -f custom-values.yaml --namespace api7ee
+helm install my-api7ee api7ee/api7ee-demo-k8s -f custom-values.yaml --namespace api7ee
 
 # Install with specific image tags
-helm install my-api7ee api7ee/api7ee \
+helm install my-api7ee api7ee/api7ee-demo-k8s \
   --set web.image.tag=v1.0.0 \
   --set api.image.tag=v1.0.0 \
   --namespace api7ee
@@ -178,7 +178,7 @@ Key Helm values:
 
 ```bash
 # Upgrade the release
-helm upgrade my-api7ee api7ee/api7ee --namespace api7ee
+helm upgrade my-api7ee api7ee/api7ee-demo-k8s --namespace api7ee
 
 # Uninstall
 helm uninstall my-api7ee --namespace api7ee