feat: seed global billing settings in application_settings

priv/repo/migrations/20260306192611_seed_billing_settings.exs

@@ -0,0 +1,22 @@
+defmodule Towerops.Repo.Migrations.SeedBillingSettings do
+  use Ecto.Migration
+
+  def up do
+    execute """
+    INSERT INTO application_settings (id, key, value, value_type, description, inserted_at, updated_at)
+    VALUES
+      (gen_random_uuid(), 'default_free_devices', '10', 'integer',
+       'Number of free devices included in all subscriptions', NOW(), NOW()),
+      (gen_random_uuid(), 'default_price_per_device', '2.00', 'string',
+       'Price per device per month (USD) after free tier', NOW(), NOW())
+    ON CONFLICT (key) DO NOTHING;
+    """
+  end
+
+  def down do
+    execute """
+    DELETE FROM application_settings
+    WHERE key IN ('default_free_devices', 'default_price_per_device');
+    """
+  end
+end