chore(repo): iOS-App als ios/ ins Hauptrepo uebernehmen

Calendarr-IOS wird mit vollstaendiger Historie als Unterverzeichnis
ios/ eingebunden. Damit liegen Server, Web, Android und iOS in einem
gemeinsamen Repo.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

ios/CalendarrWidgets/CalendarIntent.swift

@@ -0,0 +1,47 @@
+import AppIntents
+import WidgetKit
+
+/// An individual calendar option shown in the widget configuration picker.
+struct CalendarAppEntity: AppEntity, Identifiable {
+    let id: String
+    let name: String
+    let colorHex: String
+
+    static var typeDisplayRepresentation: TypeDisplayRepresentation = "Kalender"
+    static var defaultQuery = CalendarEntityQuery()
+
+    var displayRepresentation: DisplayRepresentation {
+        DisplayRepresentation(title: LocalizedStringResource(stringLiteral: name))
+    }
+}
+
+/// Reads available calendars from the App Group container so the widget
+/// extension can offer options without a network call.
+struct CalendarEntityQuery: EntityQuery {
+    func entities(for identifiers: [String]) async throws -> [CalendarAppEntity] {
+        let ids = Set(identifiers)
+        return WidgetStore.readCalendars()
+            .filter { ids.contains($0.id) }
+            .map { CalendarAppEntity(id: $0.id, name: $0.name, colorHex: $0.colorHex) }
+    }
+
+    func suggestedEntities() async throws -> [CalendarAppEntity] {
+        WidgetStore.readCalendars()
+            .map { CalendarAppEntity(id: $0.id, name: $0.name, colorHex: $0.colorHex) }
+    }
+}
+
+/// Widget configuration intent: lets the user pick which calendars to show.
+/// No selection means "show all calendars" (the default).
+///
+/// The parameter must be optional: WidgetConfigurationIntent requires every
+/// parameter type to be optional, and the macOS/Mac Catalyst SDK enforces that
+/// where the iOS one lets a bare array through. `nil` and `[]` are treated
+/// alike downstream, so this is behaviour-preserving.
+struct CalendarSelectionIntent: WidgetConfigurationIntent {
+    static var title: LocalizedStringResource = "Kalender auswählen"
+    static var description = IntentDescription("Wähle welche Kalender im Widget angezeigt werden. Leer = alle Kalender.")
+
+    @Parameter(title: "Kalender")
+    var selectedCalendars: [CalendarAppEntity]?
+}