Add models and migrations

priv/repo/migrations/20250606103527_create_moderations_logs.exs

@@ -0,0 +1,19 @@
+defmodule Nulla.Repo.Migrations.CreateModerationLogs do
+  use Ecto.Migration
+
+  def change do
+    create table(:moderation_logs) do
+      add :moderator_id, references(:users, on_delete: :nilify_all), null: false
+      add :target_type, :string, null: false
+      add :target_id, :string, null: false
+      add :action, :string, null: false
+      add :reason, :text
+      add :metadata, :map
+
+      timestamps()
+    end
+
+    create index(:moderation_logs, [:moderator_id])
+    create index(:moderation_logs, [:target_type, :target_id])
+  end
+end