Users can import their top tracks from Last.fm by entering their username.
No OAuth required - uses the public Last.fm API with user.getTopTracks and
user.getInfo endpoints. Includes a preview feature to verify the username
and see sample tracks before importing. Supports configurable time periods
(all time, 7 days, 1/3/6/12 months). Free tier playlist limit enforced.
- Add stripe_customer_id and stripe_subscription_id fields to User model
- Add Stripe config settings (secret key, publishable key, price ID, webhook secret)
- Create billing API endpoints: checkout session, webhook handler, portal, status
- Add frontend Billing page with upgrade/manage subscription UI
- Add billing route and Pro nav link
- Add stripe dependency to requirements
