Add calendar integrations and collaboration updates

backend/src/Socialize.Api/Modules/CalendarIntegrations/Data/CalendarCatalogEntry.cs

@@ -0,0 +1,18 @@
+namespace Socialize.Api.Modules.CalendarIntegrations.Data;
+
+public class CalendarCatalogEntry
+{
+    public Guid Id { get; init; }
+    public required string Title { get; set; }
+    public required string Description { get; set; }
+    public string? Country { get; set; }
+    public string? Region { get; set; }
+    public required string Language { get; set; }
+    public required string Category { get; set; }
+    public string? CultureOrReligion { get; set; }
+    public required string ProviderName { get; set; }
+    public required string SourceUrl { get; set; }
+    public required string TrustLevel { get; set; }
+    public required string DefaultColor { get; set; }
+    public DateTimeOffset CreatedAt { get; init; }
+}