Split cart into 4 microservices: relations, likes, orders, page-config→blog

Phase 1 - Relations service (internal): owns ContainerRelation, exposes
get-children data + attach/detach-child actions. Retargeted events, blog,
market callers from cart to relations.

Phase 2 - Likes service (internal): unified Like model replaces ProductLike
and PostLike with generic target_type/target_slug/target_id. Exposes
is-liked, liked-slugs, liked-ids data + toggle action.

Phase 3 - PageConfig → blog: moved ownership to blog with direct DB queries,
removed proxy endpoints from cart.

Phase 4 - Orders service (public): owns Order/OrderItem + SumUp checkout
flow. Cart checkout now delegates to orders via create-order action.
Webhook/return routes and reconciliation moved to orders.

Phase 5 - Infrastructure: docker-compose, deploy.sh, Dockerfiles updated
for all 3 new services. Added orders_url helper and factory model imports.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

market/alembic/env.py

@@ -9,7 +9,7 @@ MODELS = [
 TABLES = frozenset({
     "products", "product_images", "product_sections", "product_labels",
     "product_stickers", "product_attributes", "product_nutrition",
-    "product_allergens", "product_likes",
+    "product_allergens",
     "market_places", "nav_tops", "nav_subs",
     "listings", "listing_items",
     "link_errors", "link_externals", "subcategory_redirects", "product_logs",