Replace direct Post, Calendar, CalendarEntry model queries and glue
lifecycle imports with typed service calls. Cart registers all 4
services via domain_services_fn with has() guards.
Key changes:
- app.py: use domain_services_fn, Post query → services.blog
- api.py: Calendar/CalendarEntry → services.calendar
- checkout: glue order_lifecycle → services.calendar.claim/confirm
- calendar_cart: CalendarEntry → services.calendar.pending_entries()
- page_cart: Post/Calendar queries → services.blog/calendar
- global_routes: glue imports → service calls
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
