Implement display artifacts, pricing integrity, draft base and publish preview bundle

backend/alembic/versions/20260319_13_price_rules_unique_target.py

@@ -0,0 +1,38 @@
+"""price_rules unique target
+
+Revision ID: 20260319_13
+Revises: 20260319_12
+Create Date: 2026-03-19 12:40:00
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "20260319_13"
+down_revision = "20260319_12"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    conn = op.get_bind()
+
+    conn.execute(sa.text("""
+        delete from price_rules pr
+        using price_rules newer
+        where pr.scheme_id = newer.scheme_id
+          and pr.target_type = newer.target_type
+          and pr.target_ref = newer.target_ref
+          and pr.id < newer.id
+    """))
+
+    op.create_unique_constraint(
+        "uq_price_rules_scheme_target",
+        "price_rules",
+        ["scheme_id", "target_type", "target_ref"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_constraint("uq_price_rules_scheme_target", "price_rules", type_="unique")