Add supplements, kettlebell, calendar, push notifications, and PWA support

- Supplement tracking: CRUD endpoints, /today, /logs, Supplements page
- Kettlebell workouts: session tracking, analytics endpoint, ActiveSession page
- Calendar module: events CRUD, calendar components
- Push notifications: VAPID keys, PushSubscription model, APScheduler reminders,
  service worker with push/notificationclick handlers, Profile notifications UI
- PWA: vite-plugin-pwa, manifest, icons, service worker generation
- Frontend: TypeScript types, API modules, ConfirmModal, toast notifications
- Auth fixes: password hashing, nutrition endpoint auth
- CLAUDE.md: project documentation and development guide

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/api/v1/endpoints/users.py

@@ -59,6 +59,8 @@ def update_user_me(
     Update own user.
     """
     user_data = user_in.model_dump(exclude_unset=True)
+    if "password" in user_data:
+        user_data["password_hash"] = security.get_password_hash(user_data.pop("password"))
     current_user.sqlmodel_update(user_data)
     session.add(current_user)
     session.commit()