feat: Update Grafana dashboard for Kuadrant metrics and improve observability

Move Grafana dashboard to docs/samples/dashboards/ for better
organization and update dashboard metrics from token_usage to
authorized_hits/authorized_calls/limited_calls. Replace 'group' labels
with 'tier' labels for better tier-based analytics and add support for
model-specific usage tracking and namespace filtering. Enhance dashboard
with cost analysis, rate limiting visualization, and user activity
monitoring. Update deployment README and token-metrics.md to reference
new dashboard location and add comprehensive dashboard documentation
with setup instructions. Remove dependency on Grafana Operator by
storing dashboard as sample file for easier deployment and
customization.

Signed-off-by: Wen Liang <liangwen12year@gmail.com>

Author: liangwen12year

deployment/README.md

@@ -45,6 +45,17 @@ For OpenShift clusters, use the automated deployment script:
 
 This script handles all steps including feature gates, dependencies, and OpenShift-specific configurations.
 
+### 📊 Monitoring Dashboard
+
+After deployment, you can import the Grafana dashboard for monitoring:
+
+1. **Dashboard Location:** `docs/samples/dashboards/maas-token-metrics-dashboard.json`
+2. **Import into Grafana:** Upload the JSON file to your Grafana instance
+3. **Configure Prometheus:** Ensure your Prometheus datasource is configured
+4. **View Metrics:** Monitor token usage, rate limiting, and tier-based analytics
+
+See [Dashboard Documentation](../../docs/samples/dashboards/README.md) for detailed setup instructions.
+
 ### Manual Deployment Steps
 
 ### Step 0: Enable Gateway API Features (OpenShift Only)

docs/samples/dashboards/README.md

@@ -0,0 +1,97 @@
+# 📊 MaaS Grafana Dashboards
+
+This directory contains Grafana dashboard samples for the MaaS platform.
+
+## 🚀 MaaS Token Metrics Dashboard
+
+**File:** `maas-token-metrics-dashboard.json`
+
+### 📋 Overview
+
+This dashboard provides comprehensive monitoring of token usage, rate limiting, and tier-based analytics for the MaaS platform using Kuadrant/Limitador metrics.
+
+### 🎯 Key Metrics
+
+- **`authorized_hits`** - Total successful API calls with tier/user/model information
+- **`authorized_calls`** - Rate limiting success metrics  
+- **`limited_calls`** - Rate limiting block metrics
+- **`tier` labels** - Free/Premium/Enterprise tier information
+- **`model` labels** - Model-specific usage tracking
+- **`limitador_namespace`** - Namespace filtering
+
+### 📊 Dashboard Panels
+
+1. **🎯 Total Authorized Hits** - Main success metric
+2. **📈 Authorized Hits Rate by Tier** - Tier-based performance
+3. **👥 Authorized Hits by User & Tier** - User activity
+4. **🏆 Top 10 Users by Hits** - Usage leaders
+5. **⏰ Hourly Authorized Hits by User** - Time-based analysis
+6. **📊 Total Authorized Hits by Tier** - Tier comparison
+7. **👥 Active Users** - User count
+8. **💰 Top 5 Users by Cost** - Cost analysis with tier pricing
+9. **📋 Detailed Metrics Table** - Complete data view
+
+### 🔧 How to Use
+
+1. **Import into Grafana:**
+   - Go to Grafana → Dashboards → Import
+   - Upload `maas-token-metrics-dashboard.json`
+   - Configure Prometheus datasource (DS_PROMETHEUS)
+
+2. **Prerequisites:**
+   - Prometheus configured to scrape Limitador metrics
+   - ServiceMonitor for `limitador-limitador` service deployed
+   - Kuadrant policies generating metrics
+
+3. **Features:**
+   - **Tier-based filtering** - Free vs Premium vs Enterprise
+   - **User activity tracking** - Individual user usage patterns
+   - **Model usage analytics** - Which models are used most
+   - **Rate limiting monitoring** - Success vs blocked requests
+   - **Cost analysis** - Revenue tracking by tier and user
+   - **Namespace filtering** - Multi-tenant scenarios
+
+### 💰 Cost Analysis
+
+The dashboard includes cost calculations:
+- **Free Tier:** $0.005 per authorized hit
+- **Premium Tier:** $0.008 per authorized hit
+- **Enterprise Tier:** Custom pricing (configurable)
+
+### 🎨 Visual Features
+
+- **Emojis** for better visual appeal
+- **Color coding** by tier (Free=Green, Premium=Blue, Enterprise=Gold)
+- **Modern layout** with better spacing
+- **Interactive filtering** and grouping
+- **Real-time updates** (30s refresh)
+
+### 📈 Key Insights
+
+Monitor these important metrics:
+- **Success Rate:** `authorized_calls / (authorized_calls + limited_calls)`
+- **Tier Distribution:** Usage by Free/Premium/Enterprise
+- **Model Popularity:** Which models are used most
+- **User Activity:** Top users and their tier usage
+- **Cost Analysis:** Revenue by tier and user
+
+### 🔗 Related Documentation
+
+- [Deployment Guide](../../README.md)
+- [Token Metrics Guide](../../token-metrics.md)
+- [Observability Setup](../../deployment/base/observability/)
+
+### 🛠️ Customization
+
+To customize the dashboard:
+1. Import into Grafana
+2. Edit panels as needed
+3. Export updated JSON
+4. Replace this file with your custom version
+
+### 📝 Notes
+
+- Dashboard is compatible with Kuadrant v1.3.0-rc2+
+- Requires Prometheus Operator for ServiceMonitor support
+- Metrics are generated by Limitador with TelemetryPolicy
+- Dashboard auto-refreshes every 30 seconds