Fix island state preservation: revert force-dispose to dispose

The ocaml branch introduced force-dispose-islands-in for outerHTML
swaps, which destroyed hydrated islands (including their live
signals). This broke the core hypermedia+reactive pattern: the
header island's colour state was lost on navigation, and lakes
weren't being morph-updated.

Reverted to production behaviour: dispose-islands-in skips hydrated
islands. The morph algorithm then preserves them (matching by
data-sx-island name) and only morphs their lake content.

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

shared/static/scripts/sx-browser.js

@@ -14,7 +14,7 @@
   // =========================================================================
 
   var NIL = Object.freeze({ _nil: true, toString: function() { return "nil"; } });
-  var SX_VERSION = "2026-03-23T16:18:55Z";
+  var SX_VERSION = "2026-03-23T17:58:42Z";
 
   function isNil(x) { return x === NIL || x === null || x === undefined; }
   function isSxTruthy(x) { return x !== false && !isNil(x); }
@@ -4039,7 +4039,7 @@ return processElements(t); });
   return (function() {
   var selectSel = domGetAttr(el, "sx-select");
   var content = (isSxTruthy(selectSel) ? selectFromContainer(container, selectSel) : childrenToFragment(container));
-  (isSxTruthy((swapStyle == "outerHTML")) ? forceDisposeIslandsIn(target) : disposeIslandsIn(target));
+  disposeIslandsIn(target);
   return withTransition(useTransition, function() { swapDomNodes(target, content, swapStyle);
 return postSwap(target); });
 })();