docs: Add documentation for Pulse 5.0 features

- AI.md: Pulse AI assistant (chat, patrol, auto-fix)
- METRICS_HISTORY.md: Persistent metrics storage
- MAIL_GATEWAY.md: PMG monitoring support
- AUTO_UPDATE.md: One-click updates
- Updated README.md with 5.0 features section

docs/AI.md

@@ -0,0 +1,123 @@
+# Pulse AI
+
+Pulse AI is an intelligent monitoring assistant that helps you understand and manage your infrastructure through natural language conversations, proactive monitoring, and automated issue resolution.
+
+## Features
+
+### Chat Assistant
+Ask questions about your infrastructure in plain English:
+- "What's using the most CPU right now?"
+- "Show me VMs with high memory usage"
+- "Why is my backup failing?"
+- "Summarize the health of my cluster"
+
+### Patrol Mode
+Automated monitoring that runs on a schedule to:
+- Analyze resource utilization patterns
+- Detect potential issues before they cause problems
+- Generate actionable recommendations
+- Track trends over time
+
+### Auto-Fix
+Automatically resolve common issues:
+- Restart stuck services
+- Clear disk space
+- Restart unresponsive containers
+- Apply recommended optimizations
+
+### Predictive Intelligence
+- Identify resources trending toward problems
+- Forecast disk space exhaustion
+- Detect unusual patterns
+- Alert on anomalies
+
+## Configuration
+
+### Enable Pulse AI
+
+1. Navigate to **Settings → AI**
+2. Toggle **Enable Pulse AI**
+3. Configure your AI provider
+
+### Supported Providers
+
+| Provider | Models | Notes |
+|----------|--------|-------|
+| **OpenAI** | GPT-4, GPT-4 Turbo, GPT-3.5 | Recommended for best results |
+| **Anthropic** | Claude 3 Opus, Sonnet, Haiku | Excellent for complex analysis |
+| **Ollama** | Llama 3, Mistral, etc. | Self-hosted, privacy-focused |
+| **OpenRouter** | Multiple models | Pay-per-use routing |
+| **Custom** | Any OpenAI-compatible API | For enterprise deployments |
+
+### API Key Setup
+
+```bash
+# Environment variable (recommended for production)
+export PULSE_AI_PROVIDER=openai
+export PULSE_AI_API_KEY=sk-...
+
+# Or configure via Settings UI
+```
+
+### Patrol Configuration
+
+| Setting | Default | Description |
+|---------|---------|-------------|
+| Patrol Enabled | Off | Run automated checks |
+| Patrol Interval | 30 minutes | How often to run patrol |
+| Auto-Fix Enabled | Off | Allow automatic remediation |
+| Auto-Fix Model | Same as chat | Model for auto-fix decisions |
+
+## Usage
+
+### Chat Interface
+Access the AI chat from the bottom-right corner of any page. Type your question and press Enter.
+
+**Example queries:**
+```
+"What VMs are using more than 80% memory?"
+"Show me the status of all backups"
+"Why is node pve1 showing high load?"
+"Compare resource usage between this week and last week"
+```
+
+### Context Selection
+Click on any resource (VM, container, host) to add it to the AI context. This helps the AI provide more specific answers.
+
+### Patrol Reports
+When Patrol is enabled, Pulse AI will:
+1. Run periodic health checks
+2. Generate findings (issues, warnings, info)
+3. Offer to auto-fix issues (if enabled)
+4. Track trends over time
+
+## Cost Tracking
+
+Track AI API usage in **Settings → AI → Cost Dashboard**:
+- Daily/monthly usage statistics
+- Cost breakdown by feature
+- Usage trends over time
+
+## Privacy & Security
+
+- **Data stays local**: Only resource metadata is sent to AI providers
+- **No training**: Your data is never used for model training
+- **Audit logging**: All AI interactions are logged
+- **Self-hosted option**: Use Ollama for complete data privacy
+
+## Troubleshooting
+
+### AI not responding
+1. Check API key is configured correctly
+2. Verify network connectivity to AI provider
+3. Check Settings → AI for error messages
+
+### Patrol not running
+1. Ensure Patrol is enabled in Settings
+2. Check system resource availability
+3. Review logs: `journalctl -u pulse -f`
+
+### Auto-fix not working
+1. Enable Auto-Fix in Settings → AI
+2. Verify the connected agents have execute permissions
+3. Check the Auto-Fix model is configured