Switch VO2 max source to get_max_metrics (maxmet/daily endpoint)

fitnessage endpoint contains fitness age only, not VO2 max. The maxmet
endpoint (/metrics-service/metrics/maxmet/daily) is the correct source.
Keep debug logging temporarily to confirm key names from live API.

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

backend/app/services/garmin_connect_sync.py

@@ -325,32 +325,57 @@ 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 current VO2 max and fitness age once (slow-changing — only update today's row)
+    # Fetch current VO2 max once via maxmet endpoint (slow-changing — only update today's row)
     today_str = date.today().isoformat()
+    mm_data = _safe(garmin.get_max_metrics, today_str)
+    logger.info("maxmet raw response: %s", mm_data)
     fa_data = _safe(garmin.get_fitnessage_data, today_str)
     logger.info("fitnessage raw response: %s", fa_data)
+
+    vo2 = None
+    if mm_data:
+        # maxmet returns a list of metric dicts or a wrapper
+        items = mm_data if isinstance(mm_data, list) else mm_data.get("allMetrics", {}).get("metricsMap", {})
+        if isinstance(items, list):
+            for item in items:
+                for key in ("vo2MaxPreciseValue", "vo2Max", "generic"):
+                    v = item.get(key)
+                    if v and isinstance(v, (int, float)) and float(v) > 0:
+                        vo2 = float(v)
+                        break
+                if vo2:
+                    break
+        elif isinstance(items, dict):
+            for key in ("VO2_MAX", "vo2Max", "vo2MaxPreciseValue"):
+                entry = items.get(key)
+                if entry:
+                    v = entry[0].get("value") if isinstance(entry, list) else entry.get("value")
+                    if v and float(v) > 0:
+                        vo2 = float(v)
+                        break
+
+    fa_age = None
     if fa_data:
-        vo2 = (fa_data.get("vo2Max")
-               or fa_data.get("vo2MaxPreciseValue")
-               or fa_data.get("biometricProfile", {}).get("vo2Max"))
-        fa  = fa_data.get("chronologicalAge") or fa_data.get("fitnessAge")
-        logger.info("fitnessage parsed: vo2=%s fa=%s", vo2, fa)
-        if vo2 and float(vo2) > 0:
-            try:
-                fa_row = {"vo2max": float(vo2)}
-                if fa:
-                    fa_row["fitness_age"] = int(fa)
-                fa_cols = list(fa_row.keys())
-                db.execute(text(f"""
-                    INSERT INTO health_metrics (user_id, date, {", ".join(fa_cols)})
-                    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": today_str, **fa_row})
-                db.commit()
-            except Exception as exc:
-                logger.warning("Failed to upsert VO2 max: %s", exc)
-                db.rollback()
+        fa_age = fa_data.get("fitnessAge") or fa_data.get("achievableFitnessAge")
+
+    logger.info("parsed vo2=%s fitness_age=%s", vo2, fa_age)
+
+    if vo2:
+        try:
+            fa_row = {"vo2max": vo2}
+            if fa_age:
+                fa_row["fitness_age"] = int(fa_age)
+            fa_cols = list(fa_row.keys())
+            db.execute(text(f"""
+                INSERT INTO health_metrics (user_id, date, {", ".join(fa_cols)})
+                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": today_str, **fa_row})
+            db.commit()
+        except Exception as exc:
+            logger.warning("Failed to upsert VO2 max: %s", exc)
+            db.rollback()
 
     return processed