Settings sync, calendar visibility sync, event refresh & week-view fixes

- Add two-way settings sync (SettingsSync) with toggle, app-start/foreground/
  10-min pull and debounced push; server wins; view/week-start/dim-past always
  sync. Wire previously-ignored settings (hour height, contrasts, week start,
  default view, dim past) into the actual UI.
- Make AppSettings decoding resilient (decodeIfPresent) so getSettings no longer
  fails on iOS-only fields the server omits; keep text/bg/line colors local-only;
  month divider/label colors now sync.
- Auto-refresh after create/edit (cache-busting) and optimistic removal on
  delete; switch delete confirm to a centered alert. Add HA event deletion.
- Calendar visibility: fix inverted hide/show toggle; normalize calendar keys so
  local filtering works for all sources; sync banish with server sidebar_hidden
  (CalDAV/Google/HA), refetch on un-banish.
- Manual "sync with server" button in the menu.
- Upcoming widget shows next 5 days (renamed).
- Week/Day view: route multi-day timed events to the all-day strip so they no
  longer render as a full-height block.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Calendarr iOS/Views/Calendar/TimeGridView.swift

@@ -1,10 +1,54 @@
 import SwiftUI
 
 // Shared constants used by WeekView, DayView, EventEditorSheet
-let hourHeight: CGFloat = 60
 let timeColumnWidth: CGFloat = 44
 let hours = Array(0..<24)
 
+/// Live hour-row height, driven by the synced `hourHeight` setting.
+/// Falls back to 60 when unset (fresh install / value 0). Views that lay out
+/// against this also observe `@AppStorage("hourHeight")` so their body
+/// re-renders when it changes.
+var hourHeight: CGFloat {
+    let v = UserDefaults.standard.integer(forKey: "hourHeight")
+    return v > 0 ? CGFloat(v) : 60
+}
+
+/// Opacity for secondary text (weekday headers, time labels, "+N"/"KW"),
+/// mapped from the 1–4 `textContrast` level. Level 3 ≈ the previous hard-coded
+/// look so existing installs are visually unchanged.
+func secondaryTextOpacity(_ level: Int) -> Double {
+    switch level {
+    case 1:  return 0.4
+    case 2:  return 0.55
+    case 4:  return 1.0
+    default: return 0.75
+    }
+}
+
+/// Opacity for grid lines / separators, mapped from the 1–4 `lineContrast`
+/// level. Level 3 ≈ the previous hard-coded ~0.4 look.
+func gridLineOpacity(_ level: Int) -> Double {
+    switch level {
+    case 1:  return 0.15
+    case 2:  return 0.3
+    case 4:  return 0.8
+    default: return 0.5
+    }
+}
+
+/// A timed (non-all-day) event that crosses a day boundary. Such events must
+/// NOT be placed in the hourly grid — their height would be `duration ×
+/// hourHeight`, i.e. taller than the whole day, rendering as a giant block
+/// (and, sharing one id across days, only drawing on the first day). They are
+/// shown in the all-day strip instead, like all-day events.
+func eventSpansMultipleDays(_ ev: CalEvent) -> Bool {
+    guard !ev.isAllDay, ev.endDate > ev.startDate else { return false }
+    let cal = Calendar.current
+    // End is exclusive: an event ending exactly at midnight is still single-day.
+    let lastInstant = ev.endDate.addingTimeInterval(-1)
+    return !cal.isDate(ev.startDate, inSameDayAs: lastInstant)
+}
+
 // Position helpers
 func eventTop(_ ev: CalEvent) -> CGFloat {
     let cal = Calendar.current
@@ -21,6 +65,9 @@ func eventHeight(_ ev: CalEvent) -> CGFloat {
 // Shared event block used in WeekView and DayView
 struct EventBlock: View {
     let event: CalEvent
+    @AppStorage("dimPastEvents") private var dimPast = false
+
+    private var isPast: Bool { event.endDate < .now }
 
     var body: some View {
         RoundedRectangle(cornerRadius: 4)
@@ -41,5 +88,6 @@ struct EventBlock: View {
                 .padding(4)
             }
             .padding(.horizontal, 1)
+            .opacity(dimPast && isPast ? 0.5 : 1.0)
     }
 }