Expose HRV, sleep stages, calories, and contributor scores

[lextoumbourou]

Summary

Add the additional information already available via Oura v2 API:

• Sleep struct (get sleep-details, sleep endpoint): add average HRV, total/deep/REM/light sleep duration, awake time, latency, restless periods, average & lowest heart rate, and average breath.
• DailyActivity struct (get activity, daily_activity endpoint): add active and total calories.
• DailySleep struct (get sleep, daily_sleep endpoint): add the contributors breakdown (deep sleep, efficiency, latency, REM, restfulness, timing, total sleep).
• DailyReadiness struct (get readiness, daily_readiness endpoint): add the contributors breakdown (activity balance, body temperature, HRV balance, previous day activity/night, recovery index, resting heart rate, sleep balance/regularity) plus temperature_deviation and temperature_trend_deviation.

Test plan

• go build ./..., go vet ./..., gofmt -l . all clean
• Verified live against the Oura API — new fields decode with real, non-zero values:

oura get sleep
{
  "data": [
    {
      "id": "<uuid>",
      "day": "2026-07-11",
      "score": 75,
      "timestamp": "2026-07-11T00:00:00.000+00:00",
      "contributors": {
        "deep_sleep": 75,
        "efficiency": 67,
        "latency": 37,
        "rem_sleep": 72,
        "restfulness": 70,
        "timing": 94,
        "total_sleep": 85
      }
    }
  ],
  "next_token": ""
}

oura get sleep-details --start <D-1> --end <D> (long_sleep record)
{
  "id": "<uuid>",
  "day": "2026-07-11",
  "score": 0,
  "efficiency": 78,
  "type": "long_sleep",
  "bedtime_start": "2026-07-10T20:36:59.000+10:00",
  "bedtime_end": "2026-07-11T06:18:54.000+10:00",
  "hypnogram_5min": "",
  "total_sleep_duration": 27120,
  "time_in_bed": 34915,
  "deep_sleep_duration": 3750,
  "rem_sleep_duration": 4860,
  "light_sleep_duration": 18510,
  "awake_time": 7795,
  "latency": 2280,
  "restless_periods": 246,
  "average_hrv": 56,
  "average_heart_rate": 50.75,
  "lowest_heart_rate": 43,
  "average_breath": 13.5
}

oura get activity --start <D-1> --end <D>
{
  "data": [
    {
      "id": "<uuid>",
      "day": "2026-07-11",
      "score": 94,
      "steps": 1629,
      "active_calories": 72,
      "total_calories": 2093
    }
  ],
  "next_token": ""
}

oura get readiness --start <D-1> --end <D>
{
  "id": "<uuid>",
  "day": "2026-07-11",
  "score": 83,
  "timestamp": "2026-07-11T00:00:00.000+00:00",
  "contributors": {
    "activity_balance": 73,
    "body_temperature": 97,
    "hrv_balance": 88,
    "previous_day_activity": 80,
    "previous_night": 72,
    "recovery_index": 65,
    "resting_heart_rate": 100,
    "sleep_balance": 93,
    "sleep_regularity": 85
  },
  "temperature_deviation": -0.22,
  "temperature_trend_deviation": -0.05
}