feat(download): switch download buttons to direct source links

The token relay still stood between the button and the file: every click
issued a short-lived token URL, so downloads never reached the real
source address directly.

- Render direct anchors (target=_blank) to the raw source URL in the
  download box and the paid card, with inline extract-code buttons
- Retire the relay: delete Content\Download plus its init wiring, header
  query-var branch and SEO noindex branch, and drop the dead
  download-request flow from cms-download.js (cashier, scan-pay and
  error views stay)
- Keep the dl_token table and the download logs page as read-only
  history; unscheduling of the orphaned cleanup cron is preserved

inc/helpers/homepage/header-components.php

@@ -49,13 +49,10 @@ if (!function_exists('aksrt_header_slide_current_page_type')) {
 	 *
 	 * Custom rewrite requests can retain WordPress's is_home flag, so the
 	 * explicit theme surfaces must win before the home fallback is evaluated.
-	 * Utility rewrites (download token hand-off, go-link confirm) are error /
-	 * hand-off surfaces and opt out entirely, like the excluded templates.
+	 * Utility rewrites (go-link confirm) are error / hand-off surfaces and
+	 * opt out entirely, like the excluded templates.
 	 */
 	function aksrt_header_slide_current_page_type(): string {
-		if (class_exists('\AKSRT\Content\Download') && (string) get_query_var(\AKSRT\Content\Download::QUERY_VAR) !== '') {
-			return '';
-		}
 		if ((string) get_query_var('aksrt_go_redirect') !== '') {
 			return '';
 		}