fix: remove required from entities' id

also adds "Global" entity for storing global configuration

Entities/Global.cs

@@ -0,0 +1,7 @@
+namespace Shadow.Entities;
+public class Global
+{
+	public int Id { get; set; }
+	required public string Key { get; set; }
+	public string? Value { get; set; } = null;
+}