Fix upload auto-refresh, health data refresh, and HR zone recalculation

- UploadPage now polls task status every 2s and invalidates activity,
  health-summary, and health-metrics queries on completion so new
  activities and health data appear without a hard refresh
- Garmin and Strava export endpoints now return a task_id for polling
- Updating max HR in Profile triggers a background Celery task to
  recalculate hr_zones for all existing activities; profile page shows
  a confirmation note when this is queued
- Add CLAUDE.md with repo architecture and dev commands

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

backend/app/api/profile.py

@@ -55,6 +55,7 @@ async def update_profile(
     db: AsyncSession = Depends(get_db),
     current_user: User = Depends(get_current_user),
 ):
+    old_max_hr = current_user.max_heart_rate
     if body.max_heart_rate is not None:
         if not (100 <= body.max_heart_rate <= 250):
             raise HTTPException(400, "Max HR must be 100–250")
@@ -74,6 +75,11 @@ async def update_profile(
 
     await db.commit()
     await db.refresh(current_user)
+
+    if body.max_heart_rate is not None and body.max_heart_rate != old_max_hr:
+        from app.workers.tasks import recalculate_hr_zones_for_user
+        recalculate_hr_zones_for_user.delay(current_user.id, body.max_heart_rate)
+
     return {**{c.name: getattr(current_user, c.name)
                for c in User.__table__.columns},
             "estimated_max_hr": _estimated_max_hr(current_user)}

backend/app/api/upload.py

@@ -82,7 +82,7 @@ async def upload_garmin_export(
     return {
         "status": "queued",
         "activity_tasks": len(task_ids),
-        "health_task": health_task.id,
+        "task_id": health_task.id,
     }
 
 
@@ -116,6 +116,7 @@ async def upload_strava_export(
     return {
         "status": "queued",
         "activity_tasks": len(task_ids),
+        "task_id": task_ids[-1] if task_ids else None,
     }
 
 

backend/app/workers/tasks.py

@@ -439,4 +439,29 @@ def process_garmin_health_zip(zip_path: str, user_id: int):
                         "spo2": data.get("avgSpo2"),
                     })
 
-        db.commit()
+        db.commit()
+
+
+@celery_app.task(name="recalculate_hr_zones_for_user")
+def recalculate_hr_zones_for_user(user_id: int, new_max_hr: float):
+    """Recalculate hr_zones for all of a user's activities using a new max HR."""
+    from app.services.fit_parser import calculate_hr_zones
+    from app.core.database import SyncSessionLocal
+    from app.models.user import Activity, ActivityDataPoint
+    from sqlalchemy import select
+
+    with SyncSessionLocal() as db:
+        activities = db.execute(
+            select(Activity).where(Activity.user_id == user_id)
+        ).scalars().all()
+
+        for activity in activities:
+            data_points = db.execute(
+                select(ActivityDataPoint).where(ActivityDataPoint.activity_id == activity.id)
+            ).scalars().all()
+            points_dicts = [{"heart_rate": dp.heart_rate} for dp in data_points]
+            new_zones = calculate_hr_zones(points_dicts, new_max_hr)
+            if new_zones:
+                activity.hr_zones = new_zones
+
+        db.commit()