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/lib/boot-helpers.sx

@@ -346,7 +346,51 @@
         (resp-ok status get-header text)
         (when
           resp-ok
-          (dom-set-inner-html main text)
+          (let
+            ((ct (or (get-header "content-type") "")))
+            (if
+              (contains? ct "text/html")
+              (let
+                ((parser (host-new "DOMParser"))
+                  (doc (host-call parser "parseFromString" text "text/html"))
+                  (content (host-call doc "querySelector" "#sx-content")))
+                (if
+                  content
+                  (dom-set-inner-html main (host-get content "innerHTML"))
+                  (dom-set-inner-html main text)))
+              (let
+                ((container (dom-create-element "div")))
+                (let
+                  ((rendered (sx-render text)))
+                  (when
+                    rendered
+                    (dom-append container rendered)
+                    (process-oob-swaps
+                      container
+                      (fn
+                        (t oob (s :as string))
+                        (dispose-islands-in t)
+                        (swap-dom-nodes
+                          t
+                          (if
+                            (= s "innerHTML")
+                            (children-to-fragment oob)
+                            oob)
+                          s)
+                        (post-swap t)))
+                    (let
+                      ((content (select-from-container container "#sx-content")))
+                      (if
+                        content
+                        (do
+                          (dispose-islands-in main)
+                          (dom-set-inner-html main "")
+                          (dom-append main content))
+                        (do
+                          (dispose-islands-in main)
+                          (dom-set-inner-html
+                            main
+                            (dom-get-inner-html container))))))))))
           (post-swap main)
           (host-call (dom-window) "scrollTo" 0 scroll-y)))
       (fn (err) (log-warn (str "fetch-and-restore error: " err))))))