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>

likes/alembic/env.py

@@ -0,0 +1,12 @@
+from alembic import context
+from shared.db.alembic_env import run_alembic
+
+MODELS = [
+    "likes.models.like",
+]
+
+TABLES = frozenset({
+    "likes",
+})
+
+run_alembic(context.config, MODELS, TABLES)

likes/alembic/versions/0001_initial.py

@@ -0,0 +1,47 @@
+"""Initial likes tables
+
+Revision ID: likes_0001
+Revises: None
+Create Date: 2026-02-27
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "likes_0001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def _table_exists(conn, name):
+    result = conn.execute(sa.text(
+        "SELECT 1 FROM information_schema.tables WHERE table_schema='public' AND table_name=:t"
+    ), {"t": name})
+    return result.scalar() is not None
+
+
+def upgrade():
+    if _table_exists(op.get_bind(), "likes"):
+        return
+
+    op.create_table(
+        "likes",
+        sa.Column("id", sa.Integer, primary_key=True, autoincrement=True),
+        sa.Column("user_id", sa.Integer, nullable=False, index=True),
+        sa.Column("target_type", sa.String(32), nullable=False),
+        sa.Column("target_slug", sa.String(255), nullable=True),
+        sa.Column("target_id", sa.Integer, nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint("user_id", "target_type", "target_slug",
+                            name="uq_likes_user_type_slug"),
+        sa.UniqueConstraint("user_id", "target_type", "target_id",
+                            name="uq_likes_user_type_id"),
+    )
+    op.create_index("ix_likes_target", "likes", ["target_type", "target_slug"])
+
+
+def downgrade():
+    op.drop_table("likes")