- dedicated workouts section: add workouts table in database and create a dedicated page in UI (use an "objective" icon). workouts are already downloaded as dependencies of activities.
- improve synchronization: make it modal, split downloads of activities and workouts, add progress bar (which requires to know in advance how many activities or workouts will have to be downloaded).
- modern error displays: have error messages displayed in ephemeral banners with background (red for error, orange for warning, blue for notice). this should be used for login, logout, synchronisation final status in profile page (the synchronisation operation itself remains a progress bar). this modern error display should be used on all pages/tabs in case of backend is not here.