Uncommitted sx-tools changes: WASM bundles, Playwright specs, engine fixes

WASM browser bundles rebuilt with latest kernel. Playwright test specs
updated (helpers, navigation, handler-responses, hypermedia-handlers,
isomorphic, SPA navigation). Engine/boot/orchestration SX files updated.
Handler examples and not-found page refreshed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web/orchestration.sx

@@ -572,9 +572,7 @@
         (and settle-expr (not (empty? settle-expr)))
         (let
           ((exprs (sx-parse settle-expr)))
-          (for-each
-            (fn (expr) (eval-expr expr (env-extend (dict))))
-            exprs))))))
+          (for-each (fn (expr) (cek-eval expr)) exprs))))))
 
 (define
   activate-scripts
@@ -1585,12 +1583,9 @@
         (pathname (url-pathname url)))
       (when
         target
-        (if
-          (try-client-route pathname target-sel)
-          (browser-scroll-to 0 scrollY)
-          (let
-            ((headers (build-request-headers target "GET" url)))
-            (fetch-and-restore target url headers scrollY)))))))
+        (let
+          ((headers (dict "SX-Request" "true")))
+          (fetch-and-restore target url headers scrollY))))))
 
 (define
   engine-init