add database constraint to ensure tenant has a value to be used

Author: filipecabaco

priv/repo/migrations/20251204170944_nullable_jwt_secrets.exs

@@ -5,5 +5,9 @@ defmodule Realtime.Repo.Migrations.NullableJwtSecrets do
     alter table(:tenants) do
       modify :jwt_secret, :string, null: true
     end
+
+    create constraint(:tenants, :jwt_secret_or_jwt_jwks_required,
+             check: "jwt_secret IS NOT NULL OR jwt_jwks IS NOT NULL"
+           )
   end
 end