Update seller store experience

packages/database/migrations/014_collection_asset_variant_fk.sql

@@ -0,0 +1,14 @@
+SET search_path TO atlas, public;
+
+-- `workspace_id` is the tenant boundary and is never nullable. PostgreSQL's
+-- unqualified ON DELETE SET NULL on a composite FK clears every referencing
+-- column, including workspace_id. Only the optional variant pointer may be
+-- cleared when a re-collected source snapshot replaces its variants.
+ALTER TABLE collection_asset_transfers
+    DROP CONSTRAINT collection_asset_transfers_workspace_id_source_variant_id_fkey;
+
+ALTER TABLE collection_asset_transfers
+    ADD CONSTRAINT collection_asset_transfers_workspace_id_source_variant_id_fkey
+    FOREIGN KEY (workspace_id, source_variant_id)
+    REFERENCES product_variants(workspace_id, id)
+    ON DELETE SET NULL (source_variant_id);