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/engine.sx

@@ -361,9 +361,14 @@
         (=
           (dom-get-attr old-node "data-sx-island")
           (dom-get-attr new-node "data-sx-island")))
-      (do
+      (let
+        ((old-state (dom-get-attr old-node "data-sx-state"))
+          (new-state (dom-get-attr new-node "data-sx-state")))
         (sync-attrs old-node new-node)
-        (morph-island-children old-node new-node))
+        (if
+          (and new-state (not (= old-state new-state)))
+          (do (dispose-island old-node) (hydrate-island old-node))
+          (morph-island-children old-node new-node)))
       (or
         (not (= (dom-node-type old-node) (dom-node-type new-node)))
         (not (= (dom-node-name old-node) (dom-node-name new-node))))