First-class HTMX support:
- App::renderHtmx() — htmx-aware fragment / full-page rendering (HX-Target derived)
- HtmxResponse::triggerJSON() + chain-back response()
- Consolidated HTMX guide (docs/htmx.md + /htmx page), already had full HX-* header coverage

Also:
- $req / $res handler-parameter aliases (route / api / fallback / template closures)
- Env config for the whole CGI subprocess pool (ZEALPHP_CGI_WORKERS + 4 more)
- Foreground start banner for a plain 'php app.php'
- Redesigned scaffold: Terminal-Luxury theme + live htmx playground