iOS: localization fixes, per-calendar reminders, widget polish

C1 — Localization: route the remaining hardcoded German strings through
L10n (LoginView, ServerSetupView, SettingsView email, EventDetailSheet) so
"System Default" + English device language shows fully English text.

C2 — Per-calendar reminders: parse the new reminders_enabled flag on every
calendar type; CalendarStore persists a reminderDisabledKeys set and passes
it to NotificationScheduler, which skips events of muted calendars (default
and per-event reminders). Filter sheet gains a per-calendar reminder toggle
(leading swipe + bell.slash indicator), reconciled from the server and
synced back via PUT.

C3 — Widgets:
- Shared WidgetTime.range helper; Today / Today & Tomorrow / Three Days /
  Up Next now show start–end instead of only the start time.
- This Week: show up to 6 events per day (was 3) to use the height.
- Two Weeks: mini event-title pills instead of bare dots.
- Two Months: weeks expand to fill the column (no more empty lower third).
- Day & Events: smaller header/strip/rows so content stops clipping.
- Next 5 days → Next 7 days (range + labels), higher row cap.

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

CalendarrWidgets/TwoWeeksWidgetView.swift

@@ -111,19 +111,22 @@ struct TwoWeeksWidgetView: View {
                 .frame(width: 12, height: 12)
                 .background(isToday ? primary : Color.clear)
                 .clipShape(Circle())
-            // Up to 3 colored dots
-            HStack(spacing: 1) {
-                ForEach(evs.prefix(3).indices, id: \.self) { i in
-                    Circle()
-                        .fill(Color(widgetHex: evs[i].colorHex))
-                        .frame(width: 3, height: 3)
-                }
+            // Up to 2 mini event-title pills (the cell has room for titles).
+            ForEach(evs.prefix(2)) { ev in
+                Text(ev.title)
+                    .font(.system(size: 6, weight: .medium))
+                    .lineLimit(1)
+                    .foregroundStyle(.white)
+                    .padding(.horizontal, 1.5)
+                    .frame(maxWidth: .infinity, alignment: .leading)
+                    .background(Color(widgetHex: ev.colorHex))
+                    .clipShape(RoundedRectangle(cornerRadius: 1.5))
             }
-            .frame(height: 3)
-            if evs.count > 3 {
-                Text("+\(evs.count - 3)")
+            if evs.count > 2 {
+                Text("+\(evs.count - 2)")
                     .font(.system(size: 6))
                     .foregroundStyle(accent)
+                    .frame(maxWidth: .infinity, alignment: .leading)
             }
             Spacer(minLength: 0)
         }