- Build PolarProvider from scratch with proper HTTP API integration
- Add encrypted configuration loading from payment_providers table via model
- Implement sandbox/live environment switching with proper credential handling
- Fix product creation API structure for Polar.sh requirements
- Add comprehensive error handling and logging throughout checkout flow
- Fix PaymentController checkout URL handling to support Polar's checkout_url response
- Add debug logging for troubleshooting checkout session creation
- Support both regular and trial checkout flows for Polar payments