feat: implement routines feature for child and parent modes

- Added backend models for routines, routine items, and schedules.
- Created API endpoints for managing routines and their items.
- Implemented frontend components for routine creation, detail view, and assignment.
- Integrated routines into child view with a scrolling list and approval workflow.
- Added push notifications for routine confirmations and pending approvals.
- Refactored existing components to accommodate new routines functionality.
- Updated tests to cover new routines feature and ensure proper functionality.

backend/utils/push_sender.py

@@ -58,6 +58,13 @@ def send_push_to_user(user_id: str, payload: dict) -> int:
                     f'Removing stale push subscription {sub.id} for user {user_id} (HTTP {status_code})'
                 )
                 delete_subscription_by_id(sub.id)
+            elif status_code == 403 and 'VAPID credentials' in str(e):
+                # The subscription was created with a different VAPID keypair.
+                # Remove it so the client can register a fresh subscription next time.
+                logger.info(
+                    f'Removing VAPID-mismatched subscription {sub.id} for user {user_id} (HTTP 403)'
+                )
+                delete_subscription_by_id(sub.id)
             else:
                 logger.error(
                     f'WebPushException for subscription {sub.id} (user {user_id}): {e}'