feat: add core persistence model

Tiku.Domain/Tenancy/Tenant.cs

@@ -0,0 +1,40 @@
+using System.Text.Json;
+using Tiku.Domain.Common;
+
+namespace Tiku.Domain.Tenancy;
+
+public sealed class Tenant : AuditableEntity
+{
+    public string Slug { get; set; } = string.Empty;
+    public string Name { get; set; } = string.Empty;
+    public string? LegalName { get; set; }
+    public TenantStatus Status { get; set; } = TenantStatus.Active;
+    public TenantMode Mode { get; set; } = TenantMode.Saas;
+    public BillingStatus BillingStatus { get; set; } = BillingStatus.Trial;
+    public Guid? OwnerUserId { get; set; }
+    public string? LegacyId { get; set; }
+    public JsonElement Metadata { get; set; } = JsonDefaults.Object();
+}
+
+public enum TenantStatus
+{
+    Draft,
+    Active,
+    Suspended,
+    Archived
+}
+
+public enum TenantMode
+{
+    PlatformOwned,
+    Saas,
+    Dedicated
+}
+
+public enum BillingStatus
+{
+    Trial,
+    Active,
+    PastDue,
+    Cancelled
+}