Replace direct Post, MarketPlace, Calendar model queries and HTTP API
calls with typed service calls. Events registers all 4 services via
domain_services_fn with has() guards.
Key changes:
- app.py: use domain_services_fn, Post/Calendar/MarketPlace queries
→ services.blog/calendar/market, HTTP cart API → services.cart
- calendars/markets services: Post → services.blog
- post_associations: Post → services.blog, direct queries → services
- markets routes: remove unused MarketPlace import
- glue imports → shared imports throughout
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
