Refactor Helm chart for API7EE: clarify gateway requirements, improve

ADC config templating, and enhance gateway health checks

helm/api7ee-demo-k8s/README.md

@@ -7,7 +7,9 @@ A comprehensive Helm chart for deploying the API7 Enterprise Edition demo platfo
 This Helm chart provides:
 
 - **Dual Service Deployment**: Web frontend + API backend
-- **API7 Gateway Integration**: Automatic ADC (API7 Declarative CLI) configuration
+- **API7 Gateway Configuration**: Automatic ADC (API7 Declarative CLI) sync to existing gateway
+  - ⚠️ **Does NOT install API7 Gateway** - gateway must already exist
+  - Only configures routes, services, and upstreams on existing gateway
 - **TLS/SSL Management**: cert-manager integration or custom certificates
 - **Service Discovery**: Kubernetes-native service discovery
 - **Rate Limiting**: Standard and AI token-based rate limiting
@@ -47,11 +49,46 @@ This Helm chart provides:
 
 ## 📦 Prerequisites
 
+### Required
+
 - **Kubernetes**: v1.19 or higher
 - **Helm**: 3.8.0 or higher
-- **API7 Enterprise Edition**: Installed and configured
-- **Ingress Controller**: NGINX Ingress Controller (recommended)
-- **cert-manager**: v1.0+ (optional, for automatic TLS)
+- **API7 Enterprise Edition Gateway**: **MUST be already installed and running**
+  - This chart does NOT install API7 Gateway
+  - This chart only configures routes and services on an existing gateway
+  - You need the DP Manager admin URL and admin key
+  - Example: `http://api7ee3-0-xxx-dp-manager.api7ee.svc.cluster.local:7900`
+
+### Optional
+
+- **Ingress Controller**: NGINX Ingress Controller (for direct Kubernetes ingress)
+- **cert-manager**: v1.0+ (for automatic TLS certificate management)
+
+### Before Installation
+
+1. **Verify API7 Gateway is Running**:
+
+   ```bash
+   kubectl get pods -n api7ee | grep gateway
+   kubectl get pods -n api7ee | grep dp-manager
+   ```
+
+2. **Get API7 Admin Credentials**:
+
+   ```bash
+   # Get DP Manager URL
+   kubectl get svc -n api7ee | grep dp-manager
+
+   # Get admin key from API7 Dashboard or documentation
+   # Default is usually generated during API7 installation
+   ```
+
+3. **Test Gateway Connectivity**:
+   ```bash
+   # Test from within cluster
+   kubectl run test-curl --rm -i --restart=Never --image=curlimages/curl:latest \
+     -- curl -s http://api7ee3-0-xxx-dp-manager.api7ee.svc.cluster.local:7900/version
+   ```
 
 ## 🚀 Installation