feat: add join form settings

priv/repo/migrations/20260310114701_add_join_form_settings_to_settings.exs

@@ -0,0 +1,27 @@
+defmodule Mv.Repo.Migrations.AddJoinFormSettingsToSettings do
+  @moduledoc """
+  Adds join form configuration columns to the settings table.
+
+  - join_form_enabled: whether the public /join page is active
+  - join_form_field_ids: ordered list of field IDs shown on the join form (JSONB array)
+  - join_form_field_required: map of field ID => required boolean (JSONB)
+  """
+
+  use Ecto.Migration
+
+  def up do
+    alter table(:settings) do
+      add :join_form_enabled, :boolean, default: false, null: false
+      add :join_form_field_ids, {:array, :string}
+      add :join_form_field_required, :map
+    end
+  end
+
+  def down do
+    alter table(:settings) do
+      remove :join_form_enabled
+      remove :join_form_field_ids
+      remove :join_form_field_required
+    end
+  end
+end