fix: visible Liquid Glass again, group icon on group events, week today colour

- Liquid Glass: the calendar content now scrolls underneath a translucent
  safeAreaInset bar (real glass look restored) while the inline title stays
  reliable — toggling Liquid Glass is visibly different again.
- Group events are prefixed with the group's own emoji icon (from group
  settings) instead of a generic people glyph, so they're recognisable.
- Week view: today's column header now uses the configured "today" colour
  instead of the accent colour (matches the current-time line).

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

Calendarr iOS/Models/CalendarStore.swift

@@ -280,10 +280,13 @@ class CalendarStore {
     private func decorateGroupEvent(_ ev: CalEvent) -> CalEvent {
         var e = ev
         let me = UserDefaults.standard.integer(forKey: "userId")
+        // Use the group's own icon (set in group settings) so group events are
+        // recognisable; fall back to a generic people glyph.
+        let groupIcon = activeGroup?.icon ?? "👥"
         func first(_ s: String) -> String { s.split(separator: " ").first.map(String.init) ?? s }
         if ev.isGroupEvent {
-            if let c = ev.creator, c.id != me { e.title = "👥 \(first(c.displayName)): \(ev.title)" }
-            else { e.title = "👥 \(ev.title)" }
+            if let c = ev.creator, c.id != me { e.title = "\(groupIcon) \(first(c.displayName)): \(ev.title)" }
+            else { e.title = "\(groupIcon) \(ev.title)" }
         } else if let o = ev.owner, o.id != me {
             e.title = "\(first(o.displayName)): \(ev.title)"
         }