Add models and migrations

priv/repo/migrations/20250606132108_create_media_attachments.exs

@@ -0,0 +1,16 @@
+defmodule Nulla.Repo.Migrations.CreateMediaAttachments do
+  use Ecto.Migration
+
+  def change do
+    create table(:media_attachments) do
+      add :note_id, references(:notes, on_delete: :delete_all), null: false
+      add :file, :string, null: false
+      add :mime_type, :string
+      add :description, :string
+
+      timestamps(type: :utc_datetime)
+    end
+
+    create index(:media_attachments, [:note_id])
+  end
+end