Added the catalogue models and seed to support phase 6 of the POC prototype in the Persistence package.

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

@@ -158,6 +158,31 @@ enum Seed {
         ),
     ]
 
+    /// The demo cons, soonest first, each with the slugs of the shops trading there.
+    static let events: [(event: Event, shops: [String])] = [
+        (.init(slug: "dutch-comic-con", name: "Dutch Comic Con", venue: "Jaarbeurs, Utrecht", startsOn: day(2026, 9, 26), endsOn: day(2026, 9, 27)),
+         ["kestrel-row-comics", "silverfish-comics", "third-panel-supply"]),
+        (.init(slug: "stripdagen-haarlem", name: "Stripdagen Haarlem", venue: "Grote Markt, Haarlem", startsOn: day(2026, 10, 3), endsOn: day(2026, 10, 4)),
+         ["silverfish-comics"]),
+        (.init(slug: "comic-con-amsterdam", name: "Comic Con Amsterdam", venue: "RAI, Amsterdam", startsOn: day(2026, 11, 21), endsOn: day(2026, 11, 22)),
+         ["kestrel-row-comics", "inkwell-and-staple"]),
+        (.init(slug: "comic-con-brussels", name: "Comic Con Brussels", venue: "Tour & Taxis, Brussels", startsOn: day(2026, 12, 5), endsOn: day(2026, 12, 6)),
+         ["third-panel-supply"]),
+    ]
+
+    /// Noon on a day in Amsterdam, where the demo cons are dated.
+    static func day(
+        _ year: Int,
+        _ month: Int,
+        _ day: Int
+    ) -> Date {
+        var calendar = Calendar(identifier: .gregorian)
+
+        calendar.timeZone = TimeZone(identifier: "Europe/Amsterdam") ?? .gmt
+
+        return calendar.date(from: .init(year: year, month: month, day: day, hour: 12)) ?? .distantPast
+    }
+
     /// The runs the demo listings belong to.
     static let series: [Series] = [
         .init(slug: "nightward", name: "Nightward", publisher: "Meridian Comics", years: "2019–2021", issueCount: 24,