Complete Phase 2 documentation: Add HARDWARE, SERVICES, MONITORING, MAINTENANCE

Phase 2 documentation implementation:
- Created HARDWARE.md: Complete hardware inventory (servers, GPUs, storage, network cards)
- Created SERVICES.md: Service inventory with URLs, credentials, health checks (25+ services)
- Created MONITORING.md: Health monitoring recommendations, alert setup, implementation plan
- Created MAINTENANCE.md: Regular procedures, update schedules, testing checklists
- Updated README.md: Added all Phase 2 documentation links
- Updated CLAUDE.md: Cleaned up to quick reference only (1340→377 lines)

All detailed content now in specialized documentation files with cross-references.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

HOMEASSISTANT.md

@@ -131,6 +131,42 @@ curl -s -H "Authorization: Bearer $HA_TOKEN" \
 - **Philips Hue** - Lights
 - **Sonos** - Speakers
 - **Motion Sensors** - Various locations
+- **NUT (Network UPS Tools)** - UPS monitoring (added 2025-12-21)
+
+### NUT / UPS Integration
+
+Monitors the CyberPower OR2200PFCRT2U UPS connected to PVE.
+
+**Connection:**
+- Host: 10.10.10.120
+- Port: 3493
+- Username: upsmon
+- Password: upsmon123
+
+**Entities:**
+| Entity ID | Description |
+|-----------|-------------|
+| `sensor.cyberpower_battery_charge` | Battery percentage |
+| `sensor.cyberpower_load` | Current load % |
+| `sensor.cyberpower_input_voltage` | Input voltage |
+| `sensor.cyberpower_output_voltage` | Output voltage |
+| `sensor.cyberpower_status` | Status (Online, On Battery, etc.) |
+| `sensor.cyberpower_status_data` | Raw status (OL, OB, LB, CHRG) |
+
+**Dashboard Card Example:**
+```yaml
+type: entities
+title: UPS Status
+entities:
+  - entity: sensor.cyberpower_status
+    name: Status
+  - entity: sensor.cyberpower_battery_charge
+    name: Battery
+  - entity: sensor.cyberpower_load
+    name: Load
+  - entity: sensor.cyberpower_input_voltage
+    name: Input Voltage
+```
 
 ## Automations