feat: iOS Datenebene + Ersteller-Anzeige + Privat-Flag

- Modelle: CalEvent (creator, isPrivate, owner, isGroupEvent, displayColor),
  LocalCalendar (owned/sharedBy/permission/group), AppSettings
  (privateEventVisibility, groupVisibleCalendarId), UserProfile (displayName);
  neue Modelle CalGroup/GroupMember/DirectoryUser/CalendarShare.
- API: Profil-Update (Name/Login), Sharing-CRUD, Gruppen-CRUD + combined,
  Mitglieder-Farbe, iCal Import (multipart) & Export, private-Flag bei Events.
- Event-Detail zeigt "Erstellt von" (wenn != ich) + Privat-Hinweis;
  Editor hat Privat-Toggle (nur lokale Kalender). Login speichert userId.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Calendarr iOS/Models/AppSettings.swift

@@ -16,6 +16,8 @@ struct AppSettings: Codable {
     var textColor: String = "#FFFFFF"
     var backgroundColor: String = "#000000"
     var lineColor: String = "#3A3A3C"
+    var privateEventVisibility: String = "busy"   // 'hidden' | 'busy'
+    var groupVisibleCalendarId: Int? = nil
 
     enum CodingKeys: String, CodingKey {
         case defaultView = "default_view"
@@ -33,6 +35,8 @@ struct AppSettings: Codable {
         case textColor = "text_color"
         case backgroundColor = "background_color"
         case lineColor = "line_color"
+        case privateEventVisibility = "private_event_visibility"
+        case groupVisibleCalendarId = "group_visible_calendar_id"
     }
 
     init() {}
@@ -60,6 +64,8 @@ struct AppSettings: Codable {
         textColor         = try c.decodeIfPresent(String.self, forKey: .textColor)         ?? d.textColor
         backgroundColor   = try c.decodeIfPresent(String.self, forKey: .backgroundColor)   ?? d.backgroundColor
         lineColor         = try c.decodeIfPresent(String.self, forKey: .lineColor)         ?? d.lineColor
+        privateEventVisibility = try c.decodeIfPresent(String.self, forKey: .privateEventVisibility) ?? d.privateEventVisibility
+        groupVisibleCalendarId = try c.decodeIfPresent(Int.self, forKey: .groupVisibleCalendarId)
     }
 }
 
@@ -95,6 +101,27 @@ struct LocalCalendar: Codable, Identifiable {
     var name: String
     var color: String
     var enabled: Bool
+    var owned: Bool = true
+    var sharedBy: String? = nil
+    var permission: String? = nil
+    var group: Bool = false
+
+    enum CodingKeys: String, CodingKey {
+        case id, name, color, enabled, owned, permission, group
+        case sharedBy = "shared_by"
+    }
+
+    init(from decoder: Decoder) throws {
+        let c = try decoder.container(keyedBy: CodingKeys.self)
+        id        = try c.decode(Int.self, forKey: .id)
+        name      = try c.decodeIfPresent(String.self, forKey: .name) ?? ""
+        color     = try c.decodeIfPresent(String.self, forKey: .color) ?? "#34a853"
+        enabled   = try c.decodeIfPresent(Bool.self, forKey: .enabled) ?? true
+        owned     = try c.decodeIfPresent(Bool.self, forKey: .owned) ?? true
+        sharedBy  = try c.decodeIfPresent(String.self, forKey: .sharedBy)
+        permission = try c.decodeIfPresent(String.self, forKey: .permission)
+        group     = try c.decodeIfPresent(Bool.self, forKey: .group) ?? false
+    }
 }
 
 struct ICalSubscription: Codable, Identifiable {
@@ -173,6 +200,7 @@ struct HACalendar: Codable, Identifiable {
 struct UserProfile: Codable {
     let id: Int
     let username: String
+    var displayName: String?
     var email: String?
     let isAdmin: Bool
     let hasAvatar: Bool
@@ -180,12 +208,61 @@ struct UserProfile: Codable {
 
     enum CodingKeys: String, CodingKey {
         case id, username, email
+        case displayName = "display_name"
         case isAdmin = "is_admin"
         case hasAvatar = "has_avatar"
         case totpEnabled = "totp_enabled"
     }
 }
 
+// MARK: - Sharing & groups
+
+struct DirectoryUser: Codable, Identifiable {
+    let id: Int
+    let displayName: String
+    enum CodingKeys: String, CodingKey { case id; case displayName = "display_name" }
+}
+
+struct CalendarShare: Codable, Identifiable {
+    let userId: Int
+    let displayName: String?
+    var permission: String
+    var id: Int { userId }
+    enum CodingKeys: String, CodingKey {
+        case userId = "user_id"
+        case displayName = "display_name"
+        case permission
+    }
+}
+
+struct GroupMember: Codable, Identifiable {
+    let id: Int
+    let displayName: String?
+    var role: String
+    var color: String?
+    enum CodingKeys: String, CodingKey {
+        case id, role, color
+        case displayName = "display_name"
+    }
+}
+
+struct CalGroup: Codable, Identifiable {
+    let id: Int
+    var name: String
+    var icon: String?
+    var role: String?
+    var memberCount: Int?
+    var groupCalendarId: Int?
+    var groupCalendarColor: String?
+    var members: [GroupMember]?
+    enum CodingKeys: String, CodingKey {
+        case id, name, icon, role, members
+        case memberCount = "member_count"
+        case groupCalendarId = "group_calendar_id"
+        case groupCalendarColor = "group_calendar_color"
+    }
+}
+
 extension Color {
     init(hex: String) {
         let hex = hex.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)

Calendarr iOS/Models/CalEvent.swift

@@ -1,6 +1,23 @@
 import Foundation
 import SwiftUI
 
+/// Creator (or owner, in the group combined view) of an event.
+/// `id` is nil for imported events.
+struct EventPerson: Hashable {
+    let id: Int?
+    let displayName: String
+
+    static func from(_ json: Any?) -> EventPerson? {
+        guard let obj = json as? [String: Any],
+              let name = obj["display_name"] as? String, !name.isEmpty else { return nil }
+        let id: Int?
+        if let n = obj["id"] as? Int { id = n }
+        else if let s = obj["id"] as? String { id = Int(s) }
+        else { id = nil }
+        return EventPerson(id: id, displayName: name)
+    }
+}
+
 struct CalEvent: Identifiable, Hashable {
     let id: String
     let url: String
@@ -15,8 +32,15 @@ struct CalEvent: Identifiable, Hashable {
     var calendarName: String
     var calendarColor: String
     var source: String
+    var creator: EventPerson? = nil
+    var isPrivate: Bool = false
+    // Only set in the group combined view:
+    var owner: EventPerson? = nil
+    var isGroupEvent: Bool = false
+    var displayColor: String? = nil
 
-    var effectiveColor: String { color ?? calendarColor }
+    // Group view supplies a server-resolved colour; otherwise per-event then calendar colour.
+    var effectiveColor: String { displayColor ?? color ?? calendarColor }
 
     static func from(json: [String: Any]) -> CalEvent? {
         guard
@@ -49,7 +73,12 @@ struct CalEvent: Identifiable, Hashable {
             calendarId: json["calendar_id"].map { "\($0)" } ?? "",
             calendarName: json["calendar_name"] as? String ?? "",
             calendarColor: json["calendarColor"] as? String ?? "#4285f4",
-            source: json["source"] as? String ?? "local"
+            source: json["source"] as? String ?? "local",
+            creator: EventPerson.from(json["creator"]),
+            isPrivate: json["private"] as? Bool ?? false,
+            owner: EventPerson.from(json["owner"]),
+            isGroupEvent: json["is_group_event"] as? Bool ?? false,
+            displayColor: (json["display_color"] as? String).flatMap { $0.isEmpty ? nil : $0 }
         )
     }
 }

Calendarr iOS/Models/Localization.swift

@@ -201,6 +201,7 @@ private let strings: [String: [String: String]] = [
         // Event editor
         "event.title_placeholder": "Titel",
         "event.allday": "Ganztägig",
+        "event.private": "Privat",
         "event.start": "Start",
         "event.end": "Ende",
         "event.location": "Ort",
@@ -462,6 +463,7 @@ private let strings: [String: [String: String]] = [
         // Event editor
         "event.title_placeholder": "Title",
         "event.allday": "All-day",
+        "event.private": "Private",
         "event.start": "Start",
         "event.end": "End",
         "event.location": "Location",