Added the catalogue models and seed to support phase 3 of the POC prototype in the Persistence package.

Packages/Persistence/Sources/Internal/Migrations/AddTradeColumns.swift

@@ -0,0 +1,29 @@
+import FluentKit
+
+/// Adds an owner to shops and a sold date to listings.
+///
+/// Registered ahead of ``SeedCatalogue``, whose models write both columns. The owner carries no foreign key: on a fresh database the
+/// `users` table does not exist yet at this point.
+struct AddTradeColumns: AsyncMigration {
+
+    // MARK: Methods
+
+    func prepare(on database: Database) async throws {
+        try await database.schema(ShopRecord.schema)
+            .field("owner_id", .uuid)
+            .update()
+        try await database.schema(ListingRecord.schema)
+            .field("sold_at", .datetime)
+            .update()
+    }
+
+    func revert(on database: Database) async throws {
+        try await database.schema(ListingRecord.schema)
+            .deleteField("sold_at")
+            .update()
+        try await database.schema(ShopRecord.schema)
+            .deleteField("owner_id")
+            .update()
+    }
+
+}