feat(ios): toggle month view between scroll feed and paged swipe

New device-local setting "Monatsansicht seitenweise wischen" (@AppStorage, no
server sync). Off keeps the continuous vertical scroll feed; on switches the
month view to a paged TabView — one month per screen, six height-filling week
rows, swipe left/right to change month (bounded ±monthsBack/Ahead range to keep
the TabView light). WeekRow gains a fillHeight flag so the same row renders at a
fixed height (scroll) or fills the page evenly (paged); its inner cells/divider
now size to the actual geometry. Paged selection is two-way bound to the store's
current date so prev/next/today and the title stay in sync.

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

Calendarr iOS/Views/SettingsView.swift

@@ -22,6 +22,8 @@ struct SettingsView: View {
     @AppStorage("defaultView")       private var defaultView = "month"
     @AppStorage("weekStartDay")      private var weekStartDay = "monday"
     @AppStorage("dimPastEvents")     private var dimPastEvents = false
+    // Device-local: month view as horizontal paged (swipe) vs. scroll feed.
+    @AppStorage("monthViewPaged")    private var monthViewPaged = false
     @AppStorage("defaultReminderMinutes") private var defaultReminderMinutes = -1
     @AppStorage("defaultEventDurationMinutes") private var defaultEventDurationMinutes = 60
 
@@ -387,6 +389,8 @@ struct SettingsView: View {
             }
             Toggle(L10n.t("settings.dimpast", appLang), isOn: $dimPastEvents)
                 .tint(Color.accentColor)
+            Toggle(L10n.t("settings.month_paged", appLang), isOn: $monthViewPaged)
+                .tint(Color.accentColor)
         }
     }