_join_url_parts() only checked the first segment for a scheme, so passing an already-absolute URL (e.g. from cart_url()) through the |host filter would join route_prefix() + absolute URL, producing "https://host/https://host/path/". Now detects schemes in later segments and resets the base. Also add missing 'market' entry to _nav.html _app_slugs to match _nav_oob.html — without it the market menu item fell through to coop_url('/market/') instead of market_url('/'). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>