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

Packages/Persistence/Sources/Internal/Seeds/Seed.swift

@@ -11,6 +11,15 @@ enum Seed {
         ("joost@kestrelrow.example", "Joost de Wit"),
     ]
 
+    /// The seller account owning each demo shop, by the shop's slug.
+    static let owners: [(shop: String, seller: (email: String, displayName: String))] = [
+        ("kestrel-row-comics", accounts[1]),
+        ("third-panel-supply", ("hello@thirdpanel.example", "Noor Janssens")),
+        ("longbox-atlantic", ("sales@longboxatlantic.example", "Owen Pryce")),
+        ("silverfish-comics", ("shop@silverfish.example", "Fenna Bos")),
+        ("inkwell-and-staple", ("post@inkwellstaple.example", "Lukas Brandt")),
+    ]
+
     /// The demo listings, newest first.
     static let listings: [Listing] = [
         single(