Dated the demo cons in the Persistence package from the weekend after seeding, and re-dated the ones already seeded.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

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

@@ -0,0 +1,21 @@
+import FluentKit
+import Foundation
+
+/// Re-dates the demo cons from the first weekend after it runs, for databases seeded when ``CreateCommunity`` used fixed dates.
+struct RedateEvents: AsyncMigration {
+
+    // MARK: Methods
+
+    func prepare(on database: Database) async throws {
+        for (event, _) in Seed.events(after: .init()) {
+            try await EventRecord.query(on: database)
+                .filter(\.$slug == event.slug)
+                .set(\.$startsOn, to: event.startsOn)
+                .set(\.$endsOn, to: event.endsOn)
+                .update()
+        }
+    }
+
+    func revert(on database: Database) async throws {}
+
+}