OCaml evaluator for page dispatch + handler aser, 83/83 Playwright tests

Major architectural change: page function dispatch and handler execution
now go through the OCaml kernel instead of the Python bootstrapped evaluator.

OCaml integration:
- Page dispatch: bridge.eval() evaluates SX URL expressions (geography, marshes, etc.)
- Handler aser: bridge.aser() serializes handler responses as SX wire format
- _ensure_components loads all .sx files into OCaml kernel (spec, web adapter, handlers)
- defhandler/defpage registered as no-op special forms so handler files load
- helper IO primitive dispatches to Python page helpers + IO handlers
- ok-raw response format for SX wire format (no double-escaping)
- Natural list serialization in eval (no (list ...) wrapper)
- Clean pipe: _read_until_ok always sends io-response on error

SX adapter (aser):
- scope-emit!/scope-peek aliases to avoid CEK special form conflict
- aser-fragment/aser-call: strings starting with "(" pass through unserialized
- Registered cond-scheme?, is-else-clause?, primitive?, get-primitive in kernel
- random-int, parse-int as kernel primitives; json-encode, into via IO bridge

Handler migration:
- All IO calls converted to (helper "name" args...) pattern
- request-arg, request-form, state-get, state-set!, now, component-source etc.
- Fixed bare (effect ...) in island bodies leaking disposer functions as text
- Fixed lower-case → lower, ~search-results → ~examples/search-results

Reactive islands:
- sx-hydrate-islands called after client-side navigation swap
- force-dispose-islands-in for outerHTML swaps (clears hydration markers)
- clear-processed! platform primitive for re-hydration

Content restructuring:
- Design, event bridge, named stores, phase 2 consolidated into reactive overview
- Marshes split into overview + 5 example sub-pages
- Nav links use sx-get/sx-target for client-side navigation

Playwright test suite (sx/tests/test_demos.py):
- 83 tests covering hypermedia demos, reactive islands, marshes, spec explorer
- Server-side rendering, handler interactions, island hydration, navigation

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

web/boot.sx

@@ -336,11 +336,15 @@
 (define sx-hydrate-islands :effects [mutation io]
   (fn (root)
     (let ((els (dom-query-all (or root (dom-body)) "[data-sx-island]")))
+      (log-info (str "sx-hydrate-islands: " (len els) " island(s) in " (if root "subtree" "document")))
       (for-each
         (fn (el)
-          (when (not (is-processed? el "island-hydrated"))
-            (mark-processed! el "island-hydrated")
-            (hydrate-island el)))
+          (if (is-processed? el "island-hydrated")
+            (log-info (str "  skip (already hydrated): " (dom-get-attr el "data-sx-island")))
+            (do
+              (log-info (str "  hydrating: " (dom-get-attr el "data-sx-island")))
+              (mark-processed! el "island-hydrated")
+              (hydrate-island el))))
         els))))
 
 (define hydrate-island :effects [mutation io]
@@ -398,7 +402,9 @@
           (fn ((d :as lambda))
             (when (callable? d) (d)))
           disposers)
-        (dom-set-data el "sx-disposers" nil)))))
+        (dom-set-data el "sx-disposers" nil)))
+    ;; Clear hydration marker so the island can be re-hydrated
+    (clear-processed! el "island-hydrated")))
 
 (define dispose-islands-in :effects [mutation io]
   (fn (root)
@@ -416,6 +422,16 @@
               (log-info (str "disposing " (len to-dispose) " island(s)"))
               (for-each dispose-island to-dispose))))))))
 
+(define force-dispose-islands-in :effects [mutation io]
+  (fn (root)
+    ;; Dispose ALL islands in root, including hydrated ones.
+    ;; Used when the target is being completely replaced (outerHTML swap).
+    (when root
+      (let ((islands (dom-query-all root "[data-sx-island]")))
+        (when (and islands (not (empty? islands)))
+          (log-info (str "force-disposing " (len islands) " island(s)"))
+          (for-each dispose-island islands))))))
+
 
 ;; --------------------------------------------------------------------------
 ;; Render hooks — generic pre/post callbacks for hydration, swap, mount.