Add Oura Ring integration and automations documentation

- Document HACS and Oura Ring v2 integration setup
- Add OAuth credentials for Oura developer portal
- Document 9 Oura automations:
  - Sleep/wake detection (HR-based thermostat control)
  - Health alerts (low readiness, SpO2, fever detection)
  - Sleep comfort (temperature-based thermostat adjustment)
  - Activity reminders (sedentary alert)
- Add Nest thermostat to integrations list
- Mark completed TODOs

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

HOMEASSISTANT.md

@@ -130,10 +130,13 @@ curl -s -H "Authorization: Bearer $HA_TOKEN" \
 
 - **Philips Hue** - Lights
 - **Sonos** - Speakers
+- **Nest** - Thermostat (climate.thermostat)
 - **Motion Sensors** - Various locations
 - **NUT (Network UPS Tools)** - UPS monitoring (added 2025-12-21)
 - **VeSync** - Levoit humidifier control (added 2026-01-14)
 - **HomeKit Controller** - Homebridge bridge for Govee sensors (added 2026-01-14)
+- **Oura Ring v2** - Sleep/health tracking via HACS (added 2026-01-16)
+- **HACS** - Home Assistant Community Store for custom integrations
 
 ### NUT / UPS Integration
 
@@ -186,6 +189,35 @@ Controls the Levoit LV600S humidifier via VeSync cloud API.
 | `binary_sensor.lv600s_low_water` | Low water warning |
 | `binary_sensor.lv600s_water_tank_lifted` | Tank removed detection |
 
+### Oura Ring Integration (HACS)
+
+Monitors sleep, activity, and health metrics from Oura Ring via HACS custom integration.
+
+**Installation:** HACS → Integrations → Oura Ring v2
+
+**OAuth Credentials (Oura Developer Portal):**
+- Client ID: `e925a2a0-7767-4390-8b80-3a385a5b3ddc`
+- Client Secret: `xFSFSfUPihet1foWQRLAMUQbL9-kChqT_CjtHHpAxZs`
+- Redirect URI: `https://my.home-assistant.io/redirect/oauth`
+
+**Key Entities:**
+| Entity ID | Description |
+|-----------|-------------|
+| `sensor.oura_ring_readiness_score` | Daily readiness (0-100) |
+| `sensor.oura_ring_sleep_score` | Sleep quality (0-100) |
+| `sensor.oura_ring_current_heart_rate` | Current HR (bpm) |
+| `sensor.oura_ring_average_sleep_heart_rate` | Average HR during sleep |
+| `sensor.oura_ring_lowest_sleep_heart_rate` | Lowest HR during sleep |
+| `sensor.oura_ring_temperature_deviation` | Body temp deviation (°C) |
+| `sensor.oura_ring_spo2_average` | Blood oxygen (%) |
+| `sensor.oura_ring_steps` | Daily step count |
+| `sensor.oura_ring_activity_score` | Activity score (0-100) |
+
+**Troubleshooting:**
+- If sensors show "unavailable", check config entry state: `setup_retry` usually means API returned no data
+- Force sync the Oura app on your phone, then reload the integration
+- The integration polls Oura's API periodically; data updates after ring syncs to cloud
+
 ### HomeKit Controller / Homebridge Integration
 
 Connects to Homebridge running on Mac Mini to access BLE devices (Govee sensors).
@@ -241,10 +273,46 @@ Maintains 45-47% humidity for guitar storage (Lowden recommends 49% ±2%).
 - 45% turn-on, 47% turn-off creates a 2% buffer
 - Target range: 45-47% (conservatively below Lowden's 49% spec)
 
+### Oura Ring Health & Sleep Automations
+
+Uses Oura Ring biometrics for smart thermostat control and health alerts.
+
+**Sleep/Wake Detection:**
+| Automation | Trigger | Conditions | Action |
+|------------|---------|------------|--------|
+| `oura_sleep_detected_bedtime_mode` | HR < 55 bpm | Home, after 10pm | Thermostat → 66°F, front door light off, Telegram notify |
+| `oura_wake_up_detected_morning_mode` | HR > 65 bpm | Home, 5-11am, thermostat < 68°F | Thermostat → 69°F, Telegram notify |
+
+**Health Alerts:**
+| Automation | Trigger | Action |
+|------------|---------|--------|
+| `oura_low_readiness_alert` | 8am daily, readiness < 70 | Telegram: suggest rest day |
+| `oura_spo2_health_alert` | SpO2 < 94% | Urgent Telegram: health warning |
+| `oura_fever_detection_alert` | Temp deviation > 1°C | Telegram: possible illness alert |
+| `oura_sedentary_reminder` | 2pm weekdays, steps < 500 | Telegram: reminder to move |
+
+**Sleep Comfort & Recovery:**
+| Automation | Trigger | Conditions | Action |
+|------------|---------|------------|--------|
+| `oura_poor_sleep_recovery_mode` | 7am daily | Home, sleep score < 70 | Thermostat → 71°F (warmer for recovery) |
+| `oura_sleep_temp_adjustment_too_hot` | Temp deviation > +0.5°C | Home, 10pm-6am, HR < 60 | Thermostat → 64°F |
+| `oura_sleep_temp_adjustment_too_cold` | Temp deviation < -0.3°C | Home, 10pm-6am, HR < 60 | Thermostat → 68°F |
+
+**Notification Setup:**
+All notifications use `rest_command.notify_telegram` - ensure this is configured in `configuration.yaml`:
+```yaml
+rest_command:
+  notify_telegram:
+    url: "https://api.telegram.org/bot<TOKEN>/sendMessage"
+    method: POST
+    content_type: "application/json"
+    payload: '{"chat_id": "<CHAT_ID>", "text": "{{ message }}"}'
+```
+
 ## TODO
 
 - [ ] Set static IP (currently DHCP at .210, should be .110)
-- [ ] Add API token to this document
+- [x] Add API token to this document
-- [ ] Document installed integrations
+- [x] Document installed integrations
-- [ ] Document automations
+- [x] Document automations
 - [ ] Set up Traefik reverse proxy (ha.htsn.io)