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>

relations/app.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+import path_setup  # noqa: F401
+
+from shared.infrastructure.factory import create_base_app
+
+from bp import register_actions, register_data
+from services import register_domain_services
+
+
+def create_app() -> "Quart":
+    app = create_base_app(
+        "relations",
+        domain_services_fn=register_domain_services,
+    )
+
+    app.register_blueprint(register_actions())
+    app.register_blueprint(register_data())
+
+    return app
+
+
+app = create_app()