Add dark-mode business logo, payment order steps, and Arvan DNS diagnostics.

Store logo_dark_media_id on businesses, expose logoDarkUrl on tenant/website APIs, prepend awaiting-payment steps to order workflows, and surface clearer Arvan API network errors.

Co-authored-by: Cursor <cursoragent@cursor.com>

database/migrations/068_business_logo_dark.sql

@@ -0,0 +1,10 @@
+-- Optional dark-theme logo for business profile / storefront dashboards
+ALTER TABLE businesses
+  ADD COLUMN IF NOT EXISTS logo_dark_media_id BIGINT;
+
+ALTER TABLE businesses
+  DROP CONSTRAINT IF EXISTS businesses_logo_dark_media_id_fkey;
+
+ALTER TABLE businesses
+  ADD CONSTRAINT businesses_logo_dark_media_id_fkey
+  FOREIGN KEY (logo_dark_media_id) REFERENCES media (id) ON DELETE SET NULL;