Birthdays: explicit calendar creation, sync never auto-creates (iOS)

- Contacts sync fills only an EXISTING birthday calendar (birthdayCalendar),
  never auto-creates it — deleting it no longer resurrects it on sync
- Accounts + menu gains "Geburtstagskalender" (only when none exists) to create
  the single birthday calendar explicitly
- the Birthdays-from-Contacts section shows a "create one first" hint when there
  is no birthday calendar; enabling sync only requests Contacts access

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

Calendarr iOS/Models/Localization.swift

@@ -292,6 +292,7 @@ private let strings: [String: [String: String]] = [
         "accounts.loading": "Lade Konten…",
         "accounts.add.caldav": "CalDAV-Konto",
         "accounts.add.local": "Lokaler Kalender",
+        "accounts.add.birthday": "Geburtstagskalender",
         "accounts.add.ical": "iCal-URL abonnieren",
         "accounts.add.ha": "Home Assistant",
         "accounts.caldav.header": "CalDAV-Konten",
@@ -650,6 +651,7 @@ private let strings: [String: [String: String]] = [
         "accounts.loading": "Loading accounts…",
         "accounts.add.caldav": "CalDAV account",
         "accounts.add.local": "Local calendar",
+        "accounts.add.birthday": "Birthday calendar",
         "accounts.add.ical": "Subscribe to iCal URL",
         "accounts.add.ha": "Home Assistant",
         "accounts.caldav.header": "CalDAV accounts",

Calendarr iOS/Services/BirthdaysImporter.swift

@@ -141,7 +141,10 @@ enum BirthdaysImporter {
         guard isEnabled else { return }
         guard await requestAccess() else { return }
         guard let contacts = try? readContactBirthdays() else { return }
-        guard let cal = await ensureBirthdayCalendar(api: api) else { return }
+        // Only fill an EXISTING birthday calendar — never auto-create it. The
+        // calendar is created explicitly; deleting it means sync has nowhere to
+        // go (and must not resurrect it).
+        guard let cal = await birthdayCalendar(api: api) else { return }
         guard let existing = try? await api.getBirthdayEntries(calendarId: cal.id) else { return }
 
         // Only reconcile THIS device's contact rows; leave other devices'

Calendarr iOS/Views/AccountsView.swift

@@ -47,13 +47,9 @@ struct AccountsView: View {
                         haSection
                     }
                     .onChange(of: birthdaysSyncEnabled) { _, on in
-                        if on {
-                            Task {
-                                _ = await BirthdaysImporter.requestAccess()
-                                _ = await BirthdaysImporter.ensureBirthdayCalendar(api: api)
-                                await load()
-                            }
-                        }
+                        // Enabling only asks for Contacts access — it must NOT create
+                        // the birthday calendar. That's an explicit action.
+                        if on { Task { _ = await BirthdaysImporter.requestAccess() } }
                     }
                 }
             }
@@ -64,6 +60,12 @@ struct AccountsView: View {
                     Menu {
                         Button(L10n.t("accounts.add.caldav", appLang)) { showAddCalDAV = true }
                         Button(L10n.t("accounts.add.local",  appLang)) { showAddLocal  = true }
+                        // Only one birthday calendar per account.
+                        if birthdayCalendar == nil {
+                            Button(L10n.t("accounts.add.birthday", appLang)) {
+                                Task { await createBirthdayCalendar() }
+                            }
+                        }
                         Button(L10n.t("accounts.add.ical",   appLang)) { showAddICal   = true }
                         Button(L10n.t("accounts.add.ha",     appLang)) { showAddHA     = true }
                     } label: {
@@ -235,14 +237,13 @@ struct AccountsView: View {
 
     @ViewBuilder var birthdayContactsSection: some View {
         Section {
+            if let cal = birthdayCalendar {
                 Toggle(L10n.t("birthday.contacts.sync", appLang), isOn: $birthdaysSyncEnabled)
                 if birthdaysSyncEnabled {
-                if let cal = birthdayCalendar {
                     BirthdayNotifyPicker(days: $birthdayNotify, appLang: appLang)
                         .onChange(of: birthdayNotify) { _, v in
                             Task { try? await api.updateLocalCalendarBirthday(id: cal.id, notifyDaysBefore: v) }
                         }
-                }
                     Button {
                         Task { await syncBirthdays() }
                     } label: {
@@ -253,6 +254,12 @@ struct AccountsView: View {
                     }
                     .disabled(isSyncingBirthdays)
                 }
+            } else {
+                // No birthday calendar yet — sync has nothing to fill. Create one
+                // first via the + menu (never auto-created by sync).
+                Text(L10n.t("birthday.contacts.need_calendar", appLang))
+                    .font(.caption).foregroundStyle(.secondary)
+            }
         } header: {
             Text(L10n.t("birthday.contacts.header", appLang))
         } footer: {
@@ -260,6 +267,12 @@ struct AccountsView: View {
         }
     }
 
+    /// Explicitly create the single birthday calendar (from the + menu).
+    private func createBirthdayCalendar() async {
+        _ = await BirthdaysImporter.ensureBirthdayCalendar(api: api)
+        await load()
+    }
+
     private func syncBirthdays() async {
         isSyncingBirthdays = true
         defer { isSyncingBirthdays = false }