Add models and migrations

priv/repo/migrations/20250527054942_create_instance_settings.exs

@@ -0,0 +1,18 @@
+defmodule Nulla.Repo.Migrations.CreateInstanceSettings do
+  use Ecto.Migration
+
+  def change do
+    create table(:instance_settings) do
+      add :name, :string, default: "Nulla", null: false
+      add :description, :string, default: "Freedom Social Network", null: false
+      add :domain, :string, default: "localhost", null: false
+      add :registration, :boolean, default: false, null: false
+      add :max_characters, :integer, default: 5000, null: false
+      add :max_upload_size, :integer, default: 50, null: false
+      add :public_key, :string
+      add :private_key, :string
+
+      timestamps()
+    end
+  end
+end