Fetch full VO2 max history via maxmet/daily range query

Instead of storing only the most recent measurement, query the maxmet
endpoint with the full sync window (start_date to today) to populate
one row per measurement date. Falls back to training_status most-recent
value if the range query returns nothing.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/services/garmin_connect_sync.py

@@ -325,27 +325,39 @@ def sync_wellness(garmin, user_id: int, since: Optional[datetime], db,
             logger.warning("Failed to upsert health_metrics for %s: %s", day_str, exc)
             db.rollback()
 
-    # Fetch VO2 max from training status (slow-changing — store against measurement date)
+    # Fetch historical VO2 max across the full sync window via maxmet/daily range query
     today_str = date.today().isoformat()
-    ts_data = _safe(garmin.get_training_status, today_str)
     fa_data = _safe(garmin.get_fitnessage_data, today_str)
-
-    vo2 = None
-    vo2_date = today_str
-    generic = (ts_data or {}).get("mostRecentVO2Max", {}).get("generic") or {}
-    v = generic.get("vo2MaxPreciseValue") or generic.get("vo2MaxValue")
-    if v and float(v) > 0:
-        vo2 = float(v)
-        vo2_date = generic.get("calendarDate") or today_str
-
     fa_age = None
     if fa_data:
         fa_age = fa_data.get("fitnessAge") or fa_data.get("achievableFitnessAge")
 
-    if vo2:
     try:
-            fa_row = {"vo2max": vo2}
+        mm_history = garmin.connectapi(
-            if fa_age:
+            f"/metrics-service/metrics/maxmet/daily/{start_date.isoformat()}/{today_str}"
+        )
+    except Exception as exc:
+        logger.debug("maxmet history fetch failed: %s", exc)
+        mm_history = []
+
+    # Fall back to most-recent from training status if history is empty
+    if not mm_history:
+        ts_data = _safe(garmin.get_training_status, today_str)
+        generic = (ts_data or {}).get("mostRecentVO2Max", {}).get("generic") or {}
+        v = generic.get("vo2MaxPreciseValue") or generic.get("vo2MaxValue")
+        if v and float(v) > 0:
+            mm_history = [{"calendarDate": generic.get("calendarDate") or today_str,
+                           "vo2MaxPreciseValue": float(v)}]
+
+    stored = 0
+    for entry in (mm_history or []):
+        v = entry.get("vo2MaxPreciseValue") or entry.get("vo2MaxValue")
+        if not v or float(v) <= 0:
+            continue
+        entry_date = entry.get("calendarDate") or today_str
+        try:
+            fa_row = {"vo2max": float(v)}
+            if fa_age and entry_date == today_str:
                 fa_row["fitness_age"] = int(fa_age)
             fa_cols = list(fa_row.keys())
             db.execute(text(f"""
@@ -353,13 +365,16 @@ def sync_wellness(garmin, user_id: int, since: Optional[datetime], db,
                 VALUES (:user_id, :day, {", ".join(f":{c}" for c in fa_cols)})
                 ON CONFLICT (user_id, date) DO UPDATE SET
                 {", ".join(f"{c} = EXCLUDED.{c}" for c in fa_cols)}
-            """), {"user_id": user_id, "day": vo2_date, **fa_row})
+            """), {"user_id": user_id, "day": entry_date, **fa_row})
             db.commit()
-            logger.info("Stored VO2 max %.1f for %s", vo2, vo2_date)
+            stored += 1
         except Exception as exc:
-            logger.warning("Failed to upsert VO2 max: %s", exc)
+            logger.warning("Failed to upsert VO2 max for %s: %s", entry_date, exc)
             db.rollback()
 
+    if stored:
+        logger.info("Stored %d VO2 max data points", stored)
+
     return processed